Threat Intelligence / CVE / CVE-2026-31431

CVE-2026-31431 — Linux Kernel

CISA KEV
CVSS v3.1 7.8 (HIGH) · EPSS 3.9% (higher than 88.4% of all scored CVEs) · Priority 9/10 · Published 2026-04-22

As of 2026-05-03, CVE-2026-31431 is a HIGH-severity vulnerability in Linux Kernel, CVSS v3.1 7.8, EPSS 3.9% (88.4th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-05-01), with a US federal remediation deadline of 2026-05-15. Threadlinqs Intelligence links 4 tracked threat campaigns to CVE-2026-31431, most recently “CVE-2026-31431: Linux Local Privilege Escalation Actively Exploited by UMBRAL BISON Within 24 Hours of Disclosure”.

Last updated: 2026-05-03

What is CVE-2026-31431?

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.

The record classifies CVE-2026-31431 under weakness class CWE-669. Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 143 days ago.

Severity and exploitation probability

CVSS v3.1 base score
7.8 — HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS (FIRST)
3.9% probability of exploitation in the next 30 days, higher than 88.4% of all scored CVEs
CISA KEV
Listed since 2026-05-01, federal remediation deadline 2026-05-15
Threadlinqs priority
9/10 — CISA KEV-listed, which Threadlinqs floors at 9
Published
2026-04-22, last modified 2026-05-03

Is CVE-2026-31431 being exploited?

CISA added CVE-2026-31431 to the Known Exploited Vulnerabilities catalog on 2026-05-01, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-05-15 under BOD 22-01. It currently carries a trending score of 32 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-31431

The record marks a vendor fix as available for CVE-2026-31431. Vendor advisory: https://git.kernel.org/stable/c/fafe0fa2995a0f7073c1c358d7d3145bcc9aedd8. Because CVE-2026-31431 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-05-15. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2026-31431

4 tracked threats in the Threadlinqs corpus reference CVE-2026-31431, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Seeded from nvd and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.

Full detection coverage & IOCs for threats exploiting CVE-2026-31431 are available via the Threadlinqs MCP server (Purple tier). View plans →

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