{"cve":"CVE-2025-39802","nvd":{"published":"2025-09-15T13:15:35.703","modified":"2026-10-19T21:10:00.160","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlib/crypto: arm/poly1305: Fix register corruption in no-SIMD contexts\n\nRestore the SIMD usability check that was removed by commit 773426f4771b\n(\"crypto: arm/poly1305 - Add block-only interface\").\n\nThis safety check is cheap and is well worth eliminating a footgun.\nWhile the Poly1305 functions should not be called when SIMD registers\nare unusable, if they are anyway, they should just do the right thing\ninstead of corrupting random tasks' registers and/or computing incorrect\nMACs.  Fixing this is also needed for poly1305_kunit to pass.\n\nJust use may_use_simd() instead of the original crypto_simd_usable(),\nsince poly1305_kunit won't rely on crypto_simd_disabled_for_test.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/52c3e242f4d0043186b70d65460ba1767f27494a","https://git.kernel.org/stable/c/87bdfba903be7084cb3ee04032b14a81181fe413"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-39802","score":0.00252,"percentile":0.16495,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}