CVE-2026-31786Buffer overflow in drivers/xen/sys-hypervisor.c
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: Buffer overflow in drivers/xen/sys-hypervisor.c The build id returned by HYPERVISOR_xen_version(XENVER_build_id) is neither NUL terminated nor a string. The first causes a buffer overflow as sprintf in buildid_show will read and copy till it finds a NUL. 00000000 f4 91 51 f4 dd 38 9e 9d 65 47 52 eb 10 71 db 50 |..Q..8..eGR..q.P| 00000010 b9 a8 01 42 6f 2e 32 |...Bo.2| 00000017 So use a memcpy instead of sprintf to have the correct value: 00000000 f4 91 51 f4 dd 00 9e 9d 65 47 52 eb 10 71 db 50 |..Q.....eGR..q.P| 00000010 b9 a8 01 42 |...B| 00000014 (the above have a hack to embed a zero inside and check it's returned correctly). This is XSA-485 / CVE-2026-31786
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 84b7625728ea311ea35bdaa0eded53c1c56baeaa before e3af585e1728c917682b6a3de9a69b41fb9194d4; from 84b7625728ea311ea35bdaa0eded53c1c56baeaa before 8288d031a01dbacfde3fc643f7be3d23504de64d; from 84b7625728ea311ea35bdaa0eded53c1c56baeaa before f458ba102da97fafca106327086fc95f3fc764cb; 84b7625728ea311ea35bdaa0eded53c1c56baeaa builds before 4b4defd2fce3f966c25adabf46644a85558f1169; 84b7625728ea311ea35bdaa0eded53c1c56baeaa builds before 5c5ff7c7bd15bb536f44b10b3fb5b8408f344d0a; from 84b7625728ea311ea35bdaa0eded53c1c56baeaa before d5f59216650c51e5e3fcb7517c825bc8047f60ef; 84b7625728ea311ea35bdaa0eded53c1c56baeaa builds before 52cecff98bda2c51eed1c6ce9d21c5d6268fb19d; 84b7625728ea311ea35bdaa0eded53c1c56baeaa builds before 27fdbab4221b375de54bf91919798d88520c6e28 | CNA record |
linux linux_kernel linux:linux_kernel | from 4.13 before 5.10.254; from 5.11 before 5.15.204; from 5.16 before 6.1.170; from 6.2 before 6.6.137; from 6.7 before 6.12.85; from 6.13 before 6.18.26; from 6.19 before 7.0.3; 7.1; and 1 more ranges | NVD |
References
- https://git.kernel.org/stable/c/e3af585e1728c917682b6a3de9a69b41fb9194d4patch
- https://git.kernel.org/stable/c/8288d031a01dbacfde3fc643f7be3d23504de64dpatch
- https://git.kernel.org/stable/c/f458ba102da97fafca106327086fc95f3fc764cbpatch
- https://git.kernel.org/stable/c/4b4defd2fce3f966c25adabf46644a85558f1169patch
- https://git.kernel.org/stable/c/5c5ff7c7bd15bb536f44b10b3fb5b8408f344d0apatch
- https://git.kernel.org/stable/c/d5f59216650c51e5e3fcb7517c825bc8047f60efpatch
- https://git.kernel.org/stable/c/52cecff98bda2c51eed1c6ce9d21c5d6268fb19dpatch
- https://git.kernel.org/stable/c/27fdbab4221b375de54bf91919798d88520c6e28patch
- http://www.openwall.com/lists/oss-security/2026/04/28/12mailing-list, third-party-advisory
- http://xenbits.xen.org/xsa/advisory-485.htmlmailing-list, third-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.