CVE-2026-64304: Linux kernel · crypto: qat – validate RSA CRT component lengths
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +44
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2026-64304 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64304 (opens in a new tab)
- git.kernel.org/linus/b3ac78756588059729b9195fcc9f4b37d54057a5 (opens in a new tab)
- git.kernel.org/stable/c/1002719d13072a5e4be1e993aa61dffb4a604e82 (opens in a new tab)
- git.kernel.org/stable/c/3d61a214fdcda41f1ebfabbb483404032a7b4d91 (opens in a new tab)
- git.kernel.org/stable/c/500319830d76911c120dc0b9605f8c16d7702844 (opens in a new tab)
- git.kernel.org/stable/c/6d99c5fadd2df488103f64d6475b63ba6852202b (opens in a new tab)
- git.kernel.org/stable/c/6fb62b767f3e27661e8f8d2f7b85f4e098fcdb1a (opens in a new tab)
- git.kernel.org/stable/c/b3ac78756588059729b9195fcc9f4b37d54057a5 (opens in a new tab)
- git.kernel.org/stable/c/c34369473bfe92a0b46ec78d6358e30341c7f481 (opens in a new tab)
- git.kernel.org/stable/c/ce42224487c504aee4b7ff3a7342e7b4d7e28cc9 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)