CVE-2026-31678VulnerabilityPublished 19 Oct 2026Updated 26 Oct 2026

Red Hat Security Advisory: kernel security, bug fix, and enhancement update

Affects Red Hat kernel security,Source GCVE Database

Mentioned vulnerabilities

Authoritative record:CVE-2026-31678· High 7.8

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

Data as of 26 Oct 2026, 16:39 UTC

CVSS 3.1 base score

7.8High

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in bbe7bd722bfaea36aab3da6cc60fb4a05c644643, b8c56a3fc5d879c0928f207a756b0f067f06c6a8, 6931d21f87bc6d657f145798fad0bf077b82486c +3

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 25 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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 ≥ a9020fde67a6eb77f8130feff633189f99264db1, < bbe7bd722bfaea36aab3da6cc60fb4a05c644643	Fixed in bbe7bd722bfaea36aab3da6cc60fb4a05c644643
LinuxLinux	Affected ≥ a9020fde67a6eb77f8130feff633189f99264db1, < b8c56a3fc5d879c0928f207a756b0f067f06c6a8	Fixed in b8c56a3fc5d879c0928f207a756b0f067f06c6a8
LinuxLinux	Affected ≥ a9020fde67a6eb77f8130feff633189f99264db1, < 6931d21f87bc6d657f145798fad0bf077b82486c	Fixed in 6931d21f87bc6d657f145798fad0bf077b82486c
LinuxLinux	Affected ≥ a9020fde67a6eb77f8130feff633189f99264db1, < 98b726ab5e2a4811e27c28e4d041f75bba147eab	Fixed in 98b726ab5e2a4811e27c28e4d041f75bba147eab
LinuxLinux	Affected ≥ a9020fde67a6eb77f8130feff633189f99264db1, < 42f0d3d81209654c08ffdde5a34b9b92d2645896	Fixed in 42f0d3d81209654c08ffdde5a34b9b92d2645896
LinuxLinux	Affected ≥ a9020fde67a6eb77f8130feff633189f99264db1, < 9d56aced21fb9c104e8a3f3be9b21fbafe448ffc	Fixed in 9d56aced21fb9c104e8a3f3be9b21fbafe448ffc

Description

The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fix(es): * kernel: openvswitch: defer tunnel netdev_put to RCU release (CVE-2026-31678) * kernel: xfrm: espintcp: do not reuse an in-progress partial send (CVE-2026-52935) * kernel: sctp: diag: reject stale associations in dump_one path (CVE-2026-52917) * kernel: tipc: fix slab-use-after-free Read in tipc_aead_decrypt_done (CVE-2026-63801) * kernel: sctp: fix race between sctp_wait_for_connect and peeloff (CVE-2026-63971) * kernel: usb: typec: tcpm: bound altmode_desc[] per iteration in svdm_consume_modes() (CVE-2026-63962) * kernel: sctp: avoid auth_enable sysctl UAF during netns teardown (CVE-2026-68162) * kernel: tipc: clear sock->sk on the failed-insert path in tipc_sk_create() (CVE-2026-68117) * kernel: sctp: auth: verify auth requirement when auth_chunk is NULL (CVE-2026-68300) * kernel: sctp: validate stream count in sctp_process_strreset_inreq() (CVE-2026-68315) * kernel: Bluetooth: hci_sync: Fix advertising data UAFs (CVE-2026-74509) * kernel: sctp: keep chunk->transport in step with the list it is queued on (CVE-2026-74588) * kernel: sctp: validate cookie AUTH state before use (CVE-2026-74752) * kernel: smb: client: reject a tree connect response whose byte count is too small (CVE-2026-89631) * kernel: smb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2() (CVE-2026-89633) * kernel: signal: Prevent exec() race (CVE-2026-98256) * kernel: exec: Cleanup POSIX timers right after de_thread() (CVE-2026-98260) Bug Fix(es) and Enhancement(s): * [10.2.z] kselftests: mm: hugepage-mremap: Bail out! mremap: Expected failure, but call succeeded (JIRA:RHEL-181987) * [IBM 10.3 FEAT] zcrypt driver overwrite function - kernel part [rhel-10.2.z] (JIRA:RHEL-245336) * Batch: z-stream xfrm - rhel-10.2.z (NST-Core-26W38) (JIRA:RHEL-256678) * RHIVOS - [backport] S32G Driver Enablement - USB (JIRA:RHEL-257228) * Fix pending kernel issues for L1VH GA - Kernel (JIRA:RHEL-267038) * Backport 6785011f8b16 ("ipv4: validate checksum_start before completing checksum") [rhel-10.2.z] (JIRA:RHEL-280590) 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-367Time-of-check Time-of-use (TOCTOU) Race Condition (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
Implementation
The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
Implementation
When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
Architecture and Design
Limit the interleaving of operations on files from multiple processes.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V1.11.3 (opens in a new tab)
V11.1.6 (opens in a new tab)
V1.11.2 (opens in a new tab)
Attack patterns
Leveraging Race Conditions via Symbolic Links (opens in a new tab)
Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (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-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-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).
CWE-303Incorrect Implementation of Authentication Algorithm (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
Attack patterns
Reflection Attack in Authentication Protocol (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-805Buffer Access with Incorrect Length Value (opens in a new tab)
Base weaknessLikelihood of exploit: High
The product uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the 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)
Attack patterns
Overflow Buffers (opens in a new tab)
SOAP Array Overflow (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-2026:85321
Vendor Severity: high
CVE Count: 18
Additional Cves: CVE-2026-52917, CVE-2026-52935, CVE-2026-63801, CVE-2026-63962, CVE-2026-63971, CVE-2026-68117, CVE-2026-68162, CVE-2026-68300, CVE-2026-68315, CVE-2026-74509, CVE-2026-74588, CVE-2026-74752, CVE-2026-89631, CVE-2026-89633, CVE-2026-98256, CVE-2026-98260, CVE-2026-99999

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

WeaknessesCWE-367, CWE-825, CWE-125 +3

Technical details

References

Community reviews

Related threats