How severe is CVE-2026-31431?

CVE-2026-31431 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-31431?

CVE-2026-31431 affects the following packages: Kernel (Linux). Ecosystems affected: Linux.

How do I fix CVE-2026-31431?

Update Kernel to 5.10.254 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-31431 is resolved across your whole dependency graph.

How do I detect CVE-2026-31431 in my Linux dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-31431 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-31431?

O3 pinpoints whether CVE-2026-31431 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-31431 actively exploited in the wild?

Yes. There are 12 known exploit references for CVE-2026-31431, including . All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2026-31431?

CVE-2026-31431 has an EPSS (Exploit Prediction Scoring System) score of 94.5%, placing it in the 100th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2026-31431 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2026-31431 (Linux Kernel Incorrect Resource Transfer Between Spheres Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-05-01. CISA required all US federal civilian agencies to remediate this vulnerability by 2026-05-15. The required action was: "Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2026-31431?

CVE-2026-31431 is classified as CWE-669 (CWE-669), CWE-1288 (CWE-1288). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-31431 published, and has it been updated?

CVE-2026-31431 was published on April 22, 2026 and was last updated on July 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2026-05-01 — agencies required to remediate by 2026-05-15

🐧 Linux

CVE-2026-31431

HIGH

crypto: algif_aead - Revert to operating out-of-place

Published

Apr 22, 2026

Updated

Jul 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

12 known

EPSS Exploitation Probability

via FIRST.org ↗

94.5%probability of exploitation in next 30 days

Very High Risk100th percentile-2.23%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐧Kernel

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Linux packages — download data is not available via public APIs for these ecosystems.

Description

In the Linux kernel, the following vulnerability has been resolved:

crypto: algif_aead - Revert to operating out-of-place

This mostly reverts commit 72548b093ee3 except for the copying of the associated data.

There is no benefit in operating in-place in algif_aead since the source and destination come from different mappings. Get rid of all the complexity added for in-place operation and just copy the AD directly.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐧Linux	`Kernel`	≥ 4.14.0&&< 5.10.254	5.10.254

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

tgies/copy-fail-c

Cross-platform C port of the Copy Fail Linux LPE (CVE-2026-31431). Discl

⭐ 437🍴 120Jul 2026

KaraZajac/DIRTYFAIL

Detector + PoC for Linux page-cache write vulnerabilities: Copy Fail (CV

⭐ 23🍴 12Jul 2026

sgkdev/ptrace_may_dream

CVE-2026-31431-killed page-cache exploit — code exec into containers sha

⭐ 20🍴 4Jul 2026

JuanBindez/CVE-2026-31431

Copy Fail - CVE-2026-31431

⭐ 14🍴 5Jul 2026

ochebotar/copy-fail-CVE-2026-31431-detection-probe

Safe detection tooling for CVE-2026-31431 "Copy Fail" and CVE-2026-43284

⭐ 10🍴 2Jun 2026

4xura/CVE-2026-31431-Copy-Fail

Research artifacts, PoC scripts, and lab assets for the Copy Fail Linux

⭐ 6🍴 0May 2026

infiniroot/ansible-mitigate-copyfail-dirtyfrag

Simple Ansible Playbook to mitigate against CopyFail (CVE-2026-31431) an

⭐ 6🍴 0May 2026

samanzamani/copy-fail-checker

Read-only Bash checker for the Copy Fail Linux kernel vulnerability (CVE

⭐ 4🍴 1May 2026

bootsareme/copyfail-deconstructed

Easy-to-understand version of CVE-2026-31431

⭐ 3🍴 1Jul 2026

Koshmare-Blossom/Copyfail-sh

A Bash implementation of copyfail (CVE-2026-31431)

⭐ 3🍴 1Jun 2026

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Kernel to 5.10.254 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-31431 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-31431 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-31431. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In the Linux kernel, the following vulnerability has been resolved: crypto: algif_aead - Revert to operating out-of-place This mostly reverts commit 72548b093ee3 except for the copying of the associated data. There is no benefit in operating in-place in algif_aead since the source and destination come from different mappings. Get rid of all the complexity added for in-place operation and just copy the AD directly.

O3 Security · Impact-Aware SCA

Is CVE-2026-31431 in your dependencies?

O3 detects CVE-2026-31431 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works