CVE-2026-80710: Linux kernel · s390/dasd: Fix undersized format-check buffer
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 12:55 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.
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 28 Aug 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
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.
AI-suggested
A fix has been implemented in the Linux kernel to correct the buffer size calculation and prevent truncation. Users should apply the official kernel updates that include this fix. Since this is not a cloud service, remediation depends on patching the affected Linux kernel versions. Patch status is not explicitly confirmed here; check the vendor or distribution advisories for the official fixed versions and apply updates accordingly.
Description
In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Fix undersized format-check buffer fmt_buffer_size in dasd_eckd_check_device_format() is declared as int, even though one of the multiplicands, sizeof(struct eckd_count), is a size_t. The expression trkcount * rpt_max * sizeof(struct eckd_count) is therefore correctly evaluated at 64-bit width, but the result is silently truncated when it is stored back into the 32-bit fmt_buffer_size variable. For a sufficiently large track range (start_unit/stop_unit are caller-controlled) this truncation yields a buffer size far smaller than the number of tracks actually requested. kzalloc() then succeeds with an undersized allocation, while the subsequent channel program build still operates on the untruncated track count and writes past the end of that buffer. Compute the buffer size with check_mul_overflow() and keep it in a size_t, so that a value that no longer fits results in -EINVAL instead of a silently truncated allocation size.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80710 (opens in a new tab)
- git.kernel.org/stable/c/7f40b346462f563a0d6e841a77b5163d2a882a04 (opens in a new tab)
- git.kernel.org/stable/c/87f3389cd3920714c53e704778f7ca7f1cf0c39c (opens in a new tab)
- git.kernel.org/stable/c/9f88dda2f22927d22498801a92cab6a9424eaf86 (opens in a new tab)
- git.kernel.org/stable/c/aca18289c86f22d3fc2f3f6ff615286e7b1702f6 (opens in a new tab)
- git.kernel.org/stable/c/e16e0fc54120cee3c6f0362de95aab6792865857 (opens in a new tab)
- ubuntu.com/security/CVE-2026-80710 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80710 (opens in a new tab)
- git.kernel.org/linus/7f40b346462f563a0d6e841a77b5163d2a882a04 (opens in a new tab)