VulnerabilityPublished 14 Jan 2026Updated 19 Oct 2026

CVE-2025-71131: Linux kernel · Use After Free

Affects Linux kernelSource CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in ccbb96434d88e32358894c879457b33f7508e798 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score

7.5High

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

EPSS

0.3% chance of exploitation in 30 days – higher than 23% 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, 2026-06-10.

Patch

Available – fixed in ccbb96434d88e32358894c879457b33f7508e798, baf0e2d1e03ddb04781dfe7f22a654d3611f69b2, 18202537856e0fae079fed2c9308780bcff2bb9d +4

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

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

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
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: None: There is no loss of confidentiality within the impacted component.
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 14 Jan 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 ≥ 0a270321dbf948963aeb0e8382fe17d2c2eb3771, < ccbb96434d88e32358894c879457b33f7508e798	Fixed in ccbb96434d88e32358894c879457b33f7508e798
LinuxLinux	Affected ≥ 0a270321dbf948963aeb0e8382fe17d2c2eb3771, < baf0e2d1e03ddb04781dfe7f22a654d3611f69b2	Fixed in baf0e2d1e03ddb04781dfe7f22a654d3611f69b2
LinuxLinux	Affected ≥ 0a270321dbf948963aeb0e8382fe17d2c2eb3771, < 18202537856e0fae079fed2c9308780bcff2bb9d	Fixed in 18202537856e0fae079fed2c9308780bcff2bb9d
LinuxLinux	Affected ≥ 0a270321dbf948963aeb0e8382fe17d2c2eb3771, < 0279978adec6f1296af66b642cce641c6580be46	Fixed in 0279978adec6f1296af66b642cce641c6580be46
LinuxLinux	Affected ≥ 0a270321dbf948963aeb0e8382fe17d2c2eb3771, < 5476f7f8a311236604b78fcc5b2a63b3a61b0169	Fixed in 5476f7f8a311236604b78fcc5b2a63b3a61b0169
LinuxLinux	Affected ≥ 0a270321dbf948963aeb0e8382fe17d2c2eb3771, < 50fdb78b7c0bcc550910ef69c0984e751cac72fa	Fixed in 50fdb78b7c0bcc550910ef69c0984e751cac72fa

AI-suggested

A fix is available and has been applied in the Linux kernel source code. Users and administrators should update to a fixed kernel version that includes the relevant patches. Since this is a kernel-level vulnerability, applying the official kernel updates is the recommended remediation.

Description

CVE-2025-71131 is a use-after-free vulnerability in the Linux kernel's crypto subsystem related to the seqiv implementation. The flaw occurs because the code dereferences req->iv after calling crypto_aead_encrypt, which may have asynchronously freed the underlying request. This improper use can lead to invalid memory access. The issue has been fixed by avoiding use of req->iv after the encryption call and instead using a separate variable. The vulnerability has a high severity score of 7.5 and affects Linux kernel version 2.6.25.

Impact

The vulnerability can cause a use-after-free condition in the kernel, which may lead to system instability or crashes (availability impact). There is no indication of confidentiality or integrity impact. The CVSS 3.1 score is 7.5 (high severity) with network attack vector, low attack complexity, no privileges required, no user interaction, and unchanged scope.

Summary

This vulnerability in the Linux kernel's crypto seqiv code arises from dereferencing the req->iv pointer after the crypto_aead_encrypt function returns. Since crypto_aead_encrypt may complete asynchronously and free the request, accessing req->iv afterward is unsafe and leads to a use-after-free condition (CWE-416). The fix involves creating a new variable to hold the necessary data before the encryption call, preventing invalid memory access. The flaw affects Linux kernel version 2.6.25 and has been addressed in subsequent commits.

CWE-416Use After Free (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #7
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Architecture and Design · Language Selection
Choose a language that provides automatic memory management.
Implementation · Attack Surface Reduction
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).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 12:22 UTC

WeaknessesCWE-416

Technical details

References

Community reviews

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