VulnerabilityPublished 23 Jan 2026Updated 19 Oct 2026

CVE-2025-71161: Linux kernel · dm-verity: disable recursive forward error correction

Affects Linux kernelSource CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in e227d2b229c7529bd98d348efc55262ccf24ab35 : patch Linux kernel soon.

Data as of 26 Oct 2026, 12:42 UTC

CVSS 3.1 base score

7.5High

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

EPSS

0.4% chance of exploitation in 30 days – higher than 40% 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 can 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 e227d2b229c7529bd98d348efc55262ccf24ab35, d9f3e47d3fae0c101d9094bc956ed24e7a0ee801, 232948cf600fba69aff36b25d85ef91a73a35756 +3

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 23 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 ≥ a739ff3f543afbb4a041c16cd0182c8e8d366e70, < e227d2b229c7529bd98d348efc55262ccf24ab35	Fixed in e227d2b229c7529bd98d348efc55262ccf24ab35
LinuxLinux	Affected ≥ a739ff3f543afbb4a041c16cd0182c8e8d366e70, < d9f3e47d3fae0c101d9094bc956ed24e7a0ee801	Fixed in d9f3e47d3fae0c101d9094bc956ed24e7a0ee801
LinuxLinux	Affected ≥ a739ff3f543afbb4a041c16cd0182c8e8d366e70, < 232948cf600fba69aff36b25d85ef91a73a35756	Fixed in 232948cf600fba69aff36b25d85ef91a73a35756
LinuxLinux	Affected ≥ a739ff3f543afbb4a041c16cd0182c8e8d366e70, < 4220cb37406915c926c0e4a3dbab77cd9cceeb1e	Fixed in 4220cb37406915c926c0e4a3dbab77cd9cceeb1e
LinuxLinux	Affected ≥ a739ff3f543afbb4a041c16cd0182c8e8d366e70, < 897d9006e75f46f8bd7df78faa424327ae6a4bcf	Fixed in 897d9006e75f46f8bd7df78faa424327ae6a4bcf
LinuxLinux	Affected ≥ a739ff3f543afbb4a041c16cd0182c8e8d366e70, < 8b821ca892cfeeaf0bedc9fc72717294f67144d5	Fixed in 8b821ca892cfeeaf0bedc9fc72717294f67144d5

AI-suggested

The vulnerability has been fixed in multiple Linux kernel commits. Users should update their Linux kernel to a version including these fixes. Since this is not a cloud service, manual patching is required. Patch status is confirmed by fixed commits. No additional mitigation steps are indicated.

Description

CVE-2025-71161 is a high-severity vulnerability in the Linux kernel's dm-verity feature related to recursive forward error correction (FEC). The recursive correction mechanism can cause a denial-of-service by triggering excessive recursive calls, leading to a process hang. Additionally, the recursive correction does not function correctly due to shared buffer overwrites during recursion. This flaw affects Linux kernel version 4.5 and has been fixed in subsequent commits.

Impact

An attacker can cause a denial-of-service condition by exploiting the recursive FEC mechanism, which can cause the udev-worker process to become unresponsive ('D' state). There is no impact on confidentiality or integrity reported. The vulnerability does not appear to be exploitable for code execution or data corruption beyond denial-of-service.

Summary

The vulnerability in dm-verity's recursive forward error correction arises from two issues: a potential denial-of-service caused by a loop with up to 253 iterations recursively calling verity_hash_for_block up to 4 nested times, resulting in billions of iterations that can hang the udev-worker process; and a functional flaw where the shared buffer 'fio->bufs' is overwritten during recursive invocations, causing incorrect correction behavior. The Linux kernel version 4.5 is affected, and multiple commits have addressed the issue by disabling recursive FEC.

CWE-400Uncontrolled Resource Consumption (opens in a new tab)
Class weaknessLikelihood of exploit: High
The product does not properly control the allocation and maintenance of a limited resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place.
Architecture and Design
Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or; uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Regular Expression Exponential Blowup (opens in a new tab)
Sustained Client Engagement (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, 12:09 UTC

WeaknessesCWE-400

Technical details

References

Community reviews

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