CVE catalog
CVE-2026-64847
python-anyio: CVE-2026-64847
- Severity
- Medium · CVSS 6.8
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.16% · Oct 25, 2026
AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio or asyncio. Prior to 4.14.2, AnyIO starts process-pool workers with standard error connected to a pipe that the parent never drains, even though the documented behavior redirects all three standard streams. Worker code that writes enough attacker-influenced data to sys.stderr can fill the pipe and block before returning the standard-output protocol response, causing the awaiting process-pool call to remain blocked indefinitely. Applications that run untrusted or faulty worker code capable of producing substantial standard-error output are affected. This issue is fixed in version 4.14.2.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | python-anyio | sid | 4.15.1-3 | fixed |
| Debian | python-anyio | forky | 4.15.1-3 | fixed |
| Debian | python-anyio | trixie | 4.8.0-3 | vulnerable |
| Debian | python-anyio | bookworm | 3.6.2-1 | vulnerable |
| PyPI | anyio | Not reported | 4.14.2 | fixed |
| PyPI | anyio | Not reported | 4.14.2 | fixed |
| Suse | python-anyio | linux micro 6.2 | 4.8.0-160000.3.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | python-anyio | source | sid | 4.15.1-1 | not yet assigned | Not reported | [1148561] |
| Debian | python-anyio | source | forky | 4.15.1-1 | not yet assigned | Not reported | [1148561] |
| Debian | python-anyio | source | trixie | (unfixed) | not yet assigned | Not reported | [1148561] |
| Debian | python-anyio | source | bookworm | (unfixed) | not yet assigned | Not reported | [1148561] |
| PyPI | anyio | PyPI | Not reported | 4.14.2 | Not reported | GHSA-5P39-CFHJ-2XMP | Not reported |
| PyPI | anyio | PyPI | Not reported | 4.14.2 | Not reported | PYSEC-2026-4024 | Not reported |
| Suse | python-anyio | rpm | linux micro 6.2 | 4.8.0-160000.3.1 | Not reported | SUSE-SU-2026:24122-1 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [python3-anyio]Affected
Source package: [python-anyio]
Details (2)
3.6.2-1· all · bookwormAffected
dsa · python-anyio · debian · bookworm; dsa · python-anyio · debian · 12
3.6.2-1· all · bookwormAffected
dsa · python-anyio · debian · bookworm; dsa · python-anyio · debian · 12
[Debian 13 (Trixie)]
- [python3-anyio]Affected
Source package: [python-anyio]
Details (2)
4.8.0-3· all · trixieAffected
dsa · python-anyio · debian · 13
4.8.0-3· all · trixieAffected
dsa · python-anyio · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2026_4416-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-64847]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-64847]
- [https://osv.dev/vulnerability/PYSEC-2026-4024]
- [https://osv.dev/vulnerability/SUSE-SU-2026:24122-1]
- [https://security-tracker.debian.org/tracker/CVE-2026-64847]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64847.json]
[Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]