VulnerabilityPublished 25 Jun 2026Updated 19 Oct 2026

CVE-2026-53254: Linux kernel · Bluetooth: RFCOMM: validate skb length in MCC handlers

Affects Linux kernelSource CVE Database V5

Not known to be exploited · CVSS 8.1 High · fixed in 98377e6b1a1a56561ec66a181573ea2b61b2079e : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

8.1High

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

EPSS

0.2% chance of exploitation in 30 days – higher than 19% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-10-16.

Patch

Available – fixed in 98377e6b1a1a56561ec66a181573ea2b61b2079e, 23882b828c3c8c51d0c946446a396b10abb3b16b, 08b9c1fbe78f4ad3f6250c6541cfaabdbeb81997 +4

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

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

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

Attack Vector: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: None: There is no loss of integrity within 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 Jun 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 ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 98377e6b1a1a56561ec66a181573ea2b61b2079e	Fixed in 98377e6b1a1a56561ec66a181573ea2b61b2079e
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 23882b828c3c8c51d0c946446a396b10abb3b16b	Fixed in 23882b828c3c8c51d0c946446a396b10abb3b16b
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 08b9c1fbe78f4ad3f6250c6541cfaabdbeb81997	Fixed in 08b9c1fbe78f4ad3f6250c6541cfaabdbeb81997
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 7c15c7c2878957cbfed93bcc29c13fdace464254	Fixed in 7c15c7c2878957cbfed93bcc29c13fdace464254
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 3eabc6d47a0ad22b053329997aaf0ec1e581e392	Fixed in 3eabc6d47a0ad22b053329997aaf0ec1e581e392
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 1b070ac9e99c2c2c3a8112943ca98ab6fca7f10c	Fixed in 1b070ac9e99c2c2c3a8112943ca98ab6fca7f10c

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: validate skb length in MCC handlers The RFCOMM MCC handlers cast skb->data to protocol-specific structs without validating skb->len first. A malicious remote device can send truncated MCC frames and trigger out-of-bounds reads in these handlers. Fix this by using skb_pull_data() to validate and access the required data before dereferencing it. rfcomm_recv_rpn() requires special handling since ETSI TS 07.10 allows 1-byte RPN requests. Handle this by validating only the DLCI byte first, and validating the full struct only when len > 1.

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).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

WeaknessesCWE-125

Technical details

References

Community reviews

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