CVE-2026-74751: Linux kernel · riscv: lib: Fix ZBB strnlen reading past count boundary
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.4 Critical.
Data as of 12 Nov 2026, 20:17 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 26 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 12 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-aws-6.17pkg:deb/ubuntu/linux-aws-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.14pkg:deb/ubuntu/linux-azure-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.17pkg:deb/ubuntu/linux-azure-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-fde-6.14pkg:deb/ubuntu/linux-azure-fde-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available for this vulnerability. Users should update to patched versions of the Linux kernel that include this fix. The affected versions are explicitly listed and should be upgraded. No additional mitigation steps are necessary once the kernel is updated.
Description
A critical vulnerability in the Linux kernel's RISC-V architecture implementation was fixed. The issue involved the ZBB-optimized strnlen function reading past the count boundary, potentially causing a fault when accessing memory at page boundaries. This was due to the loop loading one word beyond the allowed boundary before checking, which could trigger faults if the next page was unmapped. The fix adjusts the boundary calculation to stop at the last valid byte and adds a pre-loop guard to prevent incorrect results.