CVE-2026-63349: agronholm anyio · Incorrect Privilege Assignment
Affects agronholm anyioSource CVE Database V5
Not known to be exploited · CVSS 7.0 High : upgrade to 4.14.2 soon.
Data as of 2 Nov 2026, 22:58 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.14.2
CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 18 Sep 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 2 Nov 2026.
What to do
Upgrade agronholm anyio to 4.14.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| agronholmanyio | Affected
| Fixed in
|
PyPIanyiopkg:pypi/anyioOther 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
If you cannot patch yet, users should avoid relying on anyio.open_process() or anyio.run_process() with the extra_groups argument for privilege dropping. Consider using alternative subprocess management methods that correctly handle supplementary groups or avoid passing extra_groups in AnyIO subprocess calls.
Description
CVE-2026-63349 is a privilege assignment vulnerability in AnyIO versions 4.14.0 up to but not including 4.14.2. The issue arises because anyio.open_process() incorrectly forwards the extra_groups argument, causing child processes to retain parent supplementary groups instead of properly clearing or setting them. This affects POSIX privilege dropping correctness in applications relying on AnyIO subprocess helpers. The flaw can also cause a TypeError if conflicting arguments are supplied.
References
- github.com/agronholm/anyio/security/advisories/GHSA-3w57-8xmc-8v26 (opens in a new tab)
- github.com/agronholm/anyio/pull/1209 (opens in a new tab)
- github.com/agronholm/anyio/commit/eb562e6462ee46b1904e50b02ce00a858cdeb200 (opens in a new tab)
- github.com/agronholm/anyio/releases/tag/4.14.2 (opens in a new tab)