CVE-2025-39804

highpriority · track · 31EPSS 0.003 · 17 %ileDEEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.25% (17th) EPSS
CVSS 7.8 · high
Is it mine?
28 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

In the Linux kernel, the following vulnerability has been resolved: lib/crypto: arm64/poly1305: Fix register corruption in no-SIMD contexts Restore the SIMD usability check that was removed by commit a59e5468a921 ("crypto: arm64/poly1305 - Add block-only interface"). This safety check is cheap and is well worth eliminating a footgun. While the Poly1305 functions should not be called when SIMD registers are unusable, if they are anyway, they should just do the right thing instead of corrupting random tasks' registers and/or computing incorrect MACs. Fixing this is also needed for poly1305_kunit to pass. Just use may_use_simd() instead of the original crypto_simd_usable(), since poly1305_kunit won't rely on crypto_simd_disabled_for_test.

01

cvss

Technical severity, 0–10. One row per scoring source.

7.8
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 5.9
v3.17.8highAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondaryexploitability 3.9 · impact 3.6
v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
02

weaknesses

The CWE weakness classes this flaw belongs to.

03

affected products (28)

Products and version ranges known to be affected.

showing 20 of 28
04

advisories (1)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2025-2053Linux Kernel: Mehrere SchwachstellenDeutsch2025-09-15csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen oder nicht näher beschriebene Auswirkungen zu erzielen.

05

also known as (4)

Other names and identifiers for this entity.

06

sources

Which sources assert this record, and when.

published 2025-09-15modified 2026-10-19
07

references (7)

External citations — patches, advisories, analysis.

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