CVE-2026-23103VulnerabilityPublished 17 Sep 2026Updated 29 Oct 2026

Red Hat Security Advisory: kernel-rt security update

Affects Linux kernelSource GCVE Database

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Mentioned vulnerabilities

Authoritative record:CVE-2026-23103· High 7.8

Not known to be exploited · CVSS 7.8 High · fixed in Red Hat package updates : patch Linux kernel soon.

Data as of 29 Oct 2026, 22:47 UTC

CVSS 3.1 base score

7.8High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in d3ba32162488283c0a4c5bedd8817aec91748802, 88f83e6c9cdb46b8c8ddd0ba01393362963cf589, 70feb16e3fbfb10b15de1396557c38e99f1ab8df +4

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 8230819494b3bf284ca7262ac5f877333147b937, < d3ba32162488283c0a4c5bedd8817aec91748802	Fixed in d3ba32162488283c0a4c5bedd8817aec91748802
LinuxLinux	Affected ≥ 8230819494b3bf284ca7262ac5f877333147b937, < 88f83e6c9cdb46b8c8ddd0ba01393362963cf589	Fixed in 88f83e6c9cdb46b8c8ddd0ba01393362963cf589
LinuxLinux	Affected ≥ 8230819494b3bf284ca7262ac5f877333147b937, < 70feb16e3fbfb10b15de1396557c38e99f1ab8df	Fixed in 70feb16e3fbfb10b15de1396557c38e99f1ab8df
LinuxLinux	Affected ≥ 8230819494b3bf284ca7262ac5f877333147b937, < 6a81e2db096913d7e43aada1c350c1282e76db39	Fixed in 6a81e2db096913d7e43aada1c350c1282e76db39
LinuxLinux	Affected ≥ 8230819494b3bf284ca7262ac5f877333147b937, < 04ba6de6eff61238e5397c14ac26a6578c7735a5	Fixed in 04ba6de6eff61238e5397c14ac26a6578c7735a5
LinuxLinux	Affected ≥ 8230819494b3bf284ca7262ac5f877333147b937, < 3c149b662cbb202a450e81f938e702ba333864ad	Fixed in 3c149b662cbb202a450e81f938e702ba333864ad

Description

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements. Security Fix(es): * kernel: ipvlan: Make the addrs_lock be per port (CVE-2026-23103) * kernel: xfrm: hold dev ref until after transport_finish NF_HOOK (CVE-2026-31663) * kernel: netfilter: nf_conntrack_h323: fix OOB read in decode_choice() (CVE-2026-43233) * kernel: ipv6: prevent possible UaF in addrconf_permanent_addr() (CVE-2026-43339) * kernel: inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP (CVE-2026-46266) * kernel: flow_dissector: do not dissect PPPoE PFC frames (CVE-2026-46306) * kernel: netfilter: xt_policy: fix strict mode inbound policy matching (CVE-2026-52920) * kernel: ppp: require CAP_NET_ADMIN in target netns for unattached ioctls (CVE-2026-53075) * kernel: ipv6: sit: reload inner IPv6 header after GSO offloads (CVE-2026-53228) * kernel: IB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN (CVE-2026-53176) * kernel: netfilter: require Ethernet MAC header before using eth_hdr() (CVE-2026-53131) * kernel: netfilter: conntrack_irc: fix possible out-of-bounds read (CVE-2026-53268) * kernel: xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx() (CVE-2026-53239) * kernel: ALSA: timer: Fix UAF at snd_timer_user_params() (CVE-2026-53192) * kernel: net: guard timestamp cmsgs to real error queue skbs (CVE-2026-53223) * kernel: ipv6: mcast: Fix use-after-free when processing MLD queries (CVE-2026-53275) * kernel: ipv4: free net->ipv4.sysctl_local_reserved_ports after unregister_net_sysctl_table() (CVE-2026-64002) * kernel: ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate() (CVE-2026-63921) * kernel: xfrm: input: hold netns during deferred transport reinjection (CVE-2026-63919) * kernel: ip6: vti: Use ip6_tnl.net in vti6_changelink() (CVE-2026-63917) * kernel: Linux kernel SLIP: Out-of-bounds write due to race condition during MTU change (CVE-2026-68143) * kernel: xfrm: fix stale skb->prev after async crypto steals a GSO segment (CVE-2026-68426) * kernel: net: qrtr: fix 32-bit integer overflow in qrtr_endpoint_post() (CVE-2026-72298) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

CWE-413Improper Resource Locking (opens in a new tab)
Base weakness
The product must have exclusive access to a resource, but it does not lock or does not correctly lock that resource.
Architecture and Design
Use a non-conflicting privilege scheme.
Architecture and Design · Implementation
Use synchronization when locking a resource.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-826Premature Release of Resource During Expected Lifetime (opens in a new tab)
Base weakness
The product releases a resource that is still intended to be used by itself or another actor.
CWE-131Incorrect Calculation of Buffer Size (opens in a new tab)
Base weaknessLikelihood of exploit: High
The product does not correctly calculate the size to be used when allocating a buffer.
Implementation
When allocating a buffer for the purpose of transforming, converting, or encoding an input, allocate enough memory to handle the largest possible encoding. For example, in a routine that converts "&" characters to "&" for HTML entity encoding, the output buffer needs to be at least 5 times as large as the input…
Implementation
Understand the programming language's underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, "not-a-number" calculations, and how the language handles…
Implementation · Input Validation
Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
Attack patterns
Overflow Buffers (opens in a new tab)
Buffer Overflow via Parameter Expansion (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-825Expired Pointer Dereference (opens in a new tab)
Base weakness
The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.
Architecture and Design
Choose a language that provides automatic memory management.
Implementation
When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-1287Improper Validation of Specified Type of Input (opens in a new tab)
Base weakness
The product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-843Access of Resource Using Incompatible Type (Type Confusion) (opens in a new tab)
Base weakness
The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.
CWE-551Incorrect Behavior Order: Authorization Before Parsing and Canonicalization (opens in a new tab)
Base weakness
If a web server does not fully parse requested URLs before it examines them for authorization, it may be possible for an attacker to bypass authorization protection.
Architecture and Design
URL Inputs should be decoded and canonicalized to the application's current internal representation before being validated and processed for authorization. Make sure that your application does not decode the same input twice.
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-266Incorrect Privilege Assignment (opens in a new tab)
Base weaknessOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
A product incorrectly assigns a privilege to a particular actor, creating an unintended sphere of control for that actor.
Architecture and Design · Operation
Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
Architecture and Design · Operation · Environment Hardening
Run your code using the lowest privileges that are required to accomplish the necessary tasks. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment.
OWASP Cheat Sheets
Docker Security (opens in a new tab)
Third Party Javascript Management (opens in a new tab)
Virtual Patching (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V1.4.4 (opens in a new tab)
V1.4.5 (opens in a new tab)
V1.10.1 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-839Numeric Range Comparison Without Minimum Check (opens in a new tab)
Base weakness
The product checks a value to ensure that it is less than or equal to a maximum, but it does not also verify that the value is greater than or equal to the minimum.
Implementation · Enforcement by Conversion
If the number to be used is always expected to be positive, change the variable type from signed to unsigned or size_t.
Implementation · Input Validation
If the number to be used could have a negative value based on the specification (thus requiring a signed value), but the number should only be positive to preserve code correctness, then include a check to ensure that the value is positive.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-364Signal Handler Race Condition (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product uses a signal handler that introduces a race condition.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design
Design signal handlers to only set flags, rather than perform complex functionality. These flags can then be checked and acted upon within the main program loop.
Implementation
Only use reentrant functions within signal handlers. Also, use validation to ensure that state is consistent while performing asynchronous actions that affect the state of execution.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V1.11.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-911Improper Update of Reference Count (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product uses a reference count to manage a resource, but it does not update or incorrectly updates the reference count.
CWE-653Improper Isolation or Compartmentalization (opens in a new tab)
Class weaknessOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product does not properly compartmentalize or isolate functionality, processes, or resources that require different privilege levels, rights, or permissions.
Architecture and Design
Break up privileges between different modules, objects, or entities. Minimize the interfaces between modules and require strong access control between them.
OWASP Cheat Sheets
Secure Design Principles (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-787Out-of-bounds Write (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #5
The product writes data past the end, or before the beginning, of the intended buffer.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

GCVE source: db.gcve.eu
Csaf Category: csaf_security_advisory
Csaf Version: 2.0
Publisher: Red Hat Product Security
Advisory ID: RHSA-2026:68532
Vendor Severity: high
CVE Count: 23
Additional Cves: CVE-2026-31663, CVE-2026-43233, CVE-2026-43339, CVE-2026-46266, CVE-2026-46306, CVE-2026-52920, CVE-2026-53075, CVE-2026-53131, CVE-2026-53176, CVE-2026-53192, CVE-2026-53223, CVE-2026-53228, CVE-2026-53239, CVE-2026-53268, CVE-2026-53275, CVE-2026-63917, CVE-2026-63919, CVE-2026-63921, CVE-2026-64002, CVE-2026-68143, CVE-2026-68426, CVE-2026-72298

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

WeaknessesCWE-413, CWE-826, CWE-131 +11

Technical details

References

Community reviews

Related threats