The rencode package through 1.0.6 for Python allows an infinite loop in typecode decoding…
Priority MEDIUM 41CWE-835Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-835.
Summary
The rencode package through 1.0.6 for Python allows an infinite loop in typecode decoding (such as via ;\x2f\x7f), enabling a remote attack that consumes CPU and memory.
Why it matters now
EPSS 0.0552 92nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | rencode (PyPI) | up to 1.0.6 | — | No fix listed | GHSA-gh8j-2pgf-x458 |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- rencode (PyPI) Vendor— Affected up to 1.0.6 Fixed in — No fix listed GHSA-gh8j-2pgf-x458
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:rencode_project:rencode:*:*:*:*:*:python:*:* | up to 1.0.6 | Vulnerable | Rencode Project |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 34 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* | 35 | Vulnerable | Fedoraproject |
- cpe:2.3:a:rencode_project:rencode:*:*:*:*:*:python:*:* Versions up to 1.0.6 Vulnerable ·Rencode Project
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* Versions 35 Vulnerable ·Fedoraproject
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-40839
- 2026-10-03 Alias added: GHSA-gh8j-2pgf-x458
References
Patch 2
Advisory 7
Other 5
- https://github.com/aresch/rencode
- https://github.com/pypa/advisory-database/tree/main/vulns/rencode/PYSEC-2021-345.yaml
- https://lists.fedoraproject.org/archives/list/[email protected]/message/BMVQRPDVSVZNGGX57CFKCYT3DEYO4QB6
- https://lists.fedoraproject.org/archives/list/[email protected]/message/MCLETLGVM5DBX6QNHQFW6TWGO5T3DENY
- https://security.netapp.com/advisory/ntap-20211008-0001
Sources
- CVE-2021-40839 · CVE Program
- CVE-2021-40839 · NVD
- FIRST EPSS
- GHSA-gh8j-2pgf-x458 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-40839 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences