CVE-2026-64847

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Source
https://cve.org/CVERecord?id=CVE-2026-64847
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-64847.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-64847
Aliases
Downstream
Published
2026-09-18T17:04:32Z
Modified
2026-09-20T03:47:06Z
Severity
  • 6.8 (Medium) CVSS_V4 - 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 CVSS Calculator
Summary
AnyIO process-pool workers can block indefinitely on undrained stderr
Details

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.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-770"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64847.json"
}
References

Affected packages

Git / github.com/agronholm/anyio

Affected ranges

Type
GIT
Repo
https://github.com/agronholm/anyio
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
f1b7301c8264b0d2e8d24a5788fd29e93dea4040
Fixed
c384f99687c64c59ed8a11c3a0f11a2d57daff71
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "0"
        },
        {
            "fixed":  "4.14.2"
        }
    ],
    "source":  [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

1.*
1.0.0
1.0.0a1
1.0.0a2
1.0.0b1
1.0.0b2
1.0.0rc1
1.0.0rc2
1.1.0
1.2.0
1.2.1
1.2.2
1.2.3
1.3.0
1.3.1
1.4.0
2.*
2.0.0
2.0.0b1
2.0.0b2
2.0.0rc1
2.0.0rc2
2.0.1
2.0.2
2.1.0
3.*
3.0.0
3.0.0rc1
3.0.0rc2
3.0.0rc3
3.0.0rc4
3.0.1
3.1.0
3.2.0
3.2.1
3.3.0
3.3.1
3.3.2
3.3.3
3.3.4
3.4.0
3.5.0
3.6.0
3.6.1
4.*
4.0.0
4.0.0rc1
4.1.0
4.10.0
4.11.0
4.12.0
4.13.0
4.14.0
4.14.1
4.2.0
4.3.0
4.4.0
4.5.0
4.6.0
4.6.1
4.6.2
4.6.2.post1
4.7.0
4.8.0
4.9.0

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-64847.json"