CVE-2026-31431VulnerabilityPublished 5 May 2026Updated 9 Oct 2026

Red Hat Security Advisory: kernel security update

Affects Linux kernelSource GCVE Database

Mentioned vulnerabilities

Exploited in the wild · KEV due 15 May 2026 · public exploit available (Metasploit) · 98% EPSS : apply the vendor's fix or mitigations to Linux kernel now.

Data as of 30 Oct 2026, 06:59 UTC

Exploitation

Actively exploited

High severity · No CVSS score from NVD or the CNA

KEV deadline: 15 May 2026 US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
EPSS: 98.1% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 5 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
1 Metasploit module
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 4 days before disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

Added to CISA KEV (opens in a new tab)
exploitation confirmed
1 May 2026, 4 days before disclosure
CVE published
on cve.org
5 May 202623:54 UTC, t = 0
KEV remediation due
US federal deadline
15 May 2026, 10 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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

"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Affected software

Product	Affected	Fixed in
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =10.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fix(es): * kernel: crypto: algif_aead - Revert to operating out-of-place (CVE-2026-31431) 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-1288Improper Validation of Consistency within Input (opens in a new tab)
Base weakness
The product receives a complex input with multiple elements or fields that must be consistent with each other, but it does not validate or incorrectly validates that the input is actually consistent.
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.
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-131Incorrect Calculation of Buffer Size (opens in a new tab)
Base weaknessLikelihood of exploit: High
The product does not correctly calculate the size to be used when allocating a buffer.
Implementation
When allocating a buffer for the purpose of transforming, converting, or encoding an input, allocate enough memory to handle the largest possible encoding. For example, in a routine that converts "&" characters to "&" for HTML entity encoding, the output buffer needs to be at least 5 times as large as the input…
Implementation
Understand the programming language's underlying representation and how it interacts with numeric calculation (CWE-681). Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, "not-a-number" calculations, and how the language handles…
Implementation · Input Validation
Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
Attack patterns
Overflow Buffers (opens in a new tab)
Buffer Overflow via Parameter Expansion (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-669Incorrect Resource Transfer Between Spheres (opens in a new tab)
Class weakness
The product does not properly transfer a resource/behavior to another sphere, or improperly imports a resource/behavior from another sphere, in a manner that provides unintended control over that resource.

References

Community reviews

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Exploitation evidence

Timeline

What to do

Affected software

Description

Public exploits and detection1 Metasploit module, GitHub proofs of concept

WeaknessesCWE-1288, CWE-131, CWE-669

Technical details

References

Community reviews

Related threats