CVE-2026-64847: Torrra · AnyIO process-pool workers can block indefinitely on undrained stderr
Affects torrraSource GCVE Database
Not known to be exploited · CVSS 6.8 Medium : upgrade to 2.1.0 when convenient.
Data as of 4 Nov 2026, 06:45 UTC
- Patch
- Available – fixed in 2.1.0
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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 3 Nov 2026.
What to do
Upgrade torrra to 2.1.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewtorrrapkg:brew/torrraOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### Impact AnyIO starts process-pool workers with stderr connected to a pipe but never drains that pipe. The worker redirects stdin and stdout to /dev/null to protect its protocol, but does not redirect stderr even though the documentation says all three standard streams are redirected. Worker code that writes enough attacker-influenced data to stderr can fill the pipe, block before returning the stdout protocol response, and wedge the awaiting process-pool call. Anyone who runs untrusted or faulty code that writes too much to `stderr` is at risk. ### Patches This vulnerability will be patched in v4.14.2. ### Workarounds Closing `sys.stderr` in the target function should at least prevent the deadlock.
References
- github.com/agronholm/anyio/security/advisories/GHSA-5p39-cfhj-2xmp (opens in a new tab)
- github.com/agronholm/anyio/pull/1207 (opens in a new tab)
- github.com/agronholm/anyio/commit/f1b7301c8264b0d2e8d24a5788fd29e93dea4040 (opens in a new tab)
- github.com/agronholm/anyio (opens in a new tab)
- github.com/agronholm/anyio/releases/tag/4.14.2 (opens in a new tab)