VulnerabilityPublished 14 Jan 2026Updated 19 Oct 2026

CVE-2025-71120: Linux kernel · NULL Pointer Dereference

Affects Linux kernelSource CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in f9e53f69ac3bc4ef568b08d3542edac02e83fefd : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

7.5High

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

EPSS

0.5% chance of exploitation in 30 days – higher than 44% 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 f9e53f69ac3bc4ef568b08d3542edac02e83fefd, d4b69a6186b215d2dc1ebcab965ed88e8d41768d, a8f1e445ce3545c90d69c9e8ff8f7821825fe810 +6

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 >=4.19.99 <4.20 >=5.4.15 <5.5	Fixed in f9e53f69ac3bc4ef568b08d3542edac02e83fefd d4b69a6186b215d2dc1ebcab965ed88e8d41768d a8f1e445ce3545c90d69c9e8ff8f7821825fe810 a2c6f25ab98b423f99ccd94874d655b8bcb01a19 7452d53f293379e2c38cfa8ad0694aa46fc4788b 5.5 4dedb6a11243a5c9eb9dbb97bca3c98bd725e83d 4.20 1c8bb965e9b0559ff0f5690615a527c30f651dd8
LinuxLinux	Affected =5.5	Fixed in–

AI-suggested

The vulnerability has been fixed in multiple Linux kernel versions including 4.20, 5.5, and others as listed in the established facts. Users should upgrade to one of these fixed versions to remediate the issue. No additional mitigation is required beyond applying the official patches.

Description

CVE-2025-71120 is a high-severity vulnerability in the Linux kernel's SUNRPC svcauth_gss module. It involves a NULL pointer dereference caused by handling a zero-length gss_token in the gss_read_proxy_verf function. This flaw can lead to a kernel crash (denial of service) due to an unconditional memory access on a NULL pointer. The issue affects certain Linux kernel versions prior to fixes being applied.

Impact

This vulnerability can cause a denial of service by crashing the Linux kernel due to a NULL pointer dereference. There is no indication of confidentiality or integrity impact. No known exploits are reported in the wild.

Summary

The vulnerability occurs because when a zero-length gss_token is processed, the pages count is zero and the first page pointer is NULL. The code attempts to access the memory address of this NULL pointer unconditionally during a memcpy operation, which can cause a NULL pointer dereference even if the copy length is zero. The fix involves guarding the memcpy call to ensure it only executes when the length is greater than zero, preventing the NULL dereference.

CWE-476NULL Pointer Dereference (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #13OWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product dereferences a pointer that it expects to be valid but is NULL.
Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
Requirements
Select a programming language that is not susceptible to these issues.
Implementation
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
OWASP Cheat Sheets
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.7 (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

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

WeaknessesCWE-476

Technical details

References

Community reviews

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