CVE-2021-40839

low
Published 2021-09-13 · Modified 2025-10-09
CVSS v3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v2
VIR risk
2.5

Description

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.

Predictions

Exploit likelihood
30%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-40839

OS impact

OSVersionStatusFixed in
arch archaffected
debian debianbookwormfixed1.0.6-2
debian debianbullseyeaffected
debian debianforkyfixed1.0.6-2
debian debiansidfixed1.0.6-2
debian debiantrixiefixed1.0.6-2

Package impact

EcosystemPackageVulnerableFixed
python PyPIrencode<=1.0.6
python PyPIrencode<572ff74586d9b1daab904c6f7f7009ce0143bb75572ff74586d9b1daab904c6f7f7009ce0143bb75

References

Verify integrity in audit chain (admin only). AS-IS.