CVE-2026-43178: Linux kernel · procfs: fix possible double mmput() in do_procmap_query()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 11 Nov 2026, 23:24 UTC
Sources agree
| CNA (Linux) | CVSS 3.1 | 7.8 |
|---|---|---|
| ADP (redhat-SADP) | CVSS 3.1 | 7.0 |
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% 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 6 May 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 11 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Linux Linux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: procfs: fix possible double mmput() in do_procmap_query() When user provides incorrectly sized buffer for build ID for PROCMAP_QUERY we return with -ENAMETOOLONG error. After recent changes this condition happens later, after we unlocked mmap_lock/per-VMA lock and did mmput(), so original goto out is now wrong and will double-mmput() mm_struct. Fix by jumping further to clean up only vm_file and name_buf.
References
- git.kernel.org/stable/c/f9fe092084cd04deea18747f58a2304026e76aaa (opens in a new tab)
- git.kernel.org/stable/c/8adaff87db143583e08eec4f4e7788f1ef8af94d (opens in a new tab)
- git.kernel.org/stable/c/90f5e87c9b75833b9ef3a4415b92c0247f28ab2f (opens in a new tab)
- git.kernel.org/stable/c/61dc9f776705d6db6847c101b98fa4f0e9eb6fa3 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-43178 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2467227 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43178.json (opens in a new tab)