write_out_tar_header() with long usernames/groupnames · Cpio: cpio: stack-based buffer overflow
Affects MicrosoftSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 15 Nov 2026, 10:24 UTC
Thin evidence
One scorer or none| CNA (redhat) | CVSS 3.1 | 5.5 |
|---|
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 12 Nov 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 14 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Red Hat Enterprise Linux 10cpio | Affected– | Fixed in– |
| Red Hat Enterprise Linux 6cpio | Affected– | Fixed in– |
| Red Hat Enterprise Linux 7cpio | Affected– | Fixed in– |
| Red Hat Enterprise Linux 8cpio | Affected– | Fixed in– |
| Red Hat Enterprise Linux 9cpio | Affected– | Fixed in– |
| Red Hat Hardened Imagescpio | Affected– | Fixed in– |
AI-suggested
Users should monitor Microsoft Security Response Center advisories for updates.
Description
A stack-based buffer overflow vulnerability exists in the cpio utility's write_out_tar_header() function when processing long usernames or groupnames. This flaw affects specific versions of the Microsoft product identified as versions 3.0 and 4.0. No CVSS score or detailed impact information is provided, and no known exploits are reported in the wild.