DEBIAN-CVE-2026-30922

Advisory lineage Upstream: 1 Downstream: 0
Upstream
Published: 18 Mar 2026, 04:17
Last modified:15 Jun 2026, 19:06

Vulnerability Summary

Overall Risk (default)
medium
30/100
CVSS Score
7.5 HIGH
3.1 (osv_debian)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

18 Mar 2026, 04:17
Published
Vulnerability first disclosed
15 Jun 2026, 19:06
Last Modified
Vulnerability information updated

Description

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.3, the `pyasn1` library is vulnerable to a Denial of Service (DoS) attack caused by uncontrolled recursion when decoding ASN.1 data with deeply nested structures. An attacker can supply a crafted payload containing thousands of nested `SEQUENCE` (`0x30`) or `SET` (`0x31`) tags with "Indefinite Length" (`0x80`) markers. This forces the decoder to recursively call itself until the Python interpreter crashes with a `RecursionError` or consumes all available memory (OOM), crashing the host application. This is a distinct vulnerability from CVE-2026-23490 (which addressed integer overflows in OID decoding). The fix for CVE-2026-23490 (`MAX_OID_ARC_CONTINUATION_OCTETS`) does not mitigate this recursion issue. Version 0.6.3 fixes this specific issue.

CVSS Metrics

  • v3.1HIGHScore: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Systems

  • debianpyasn1

    all | all | all | all | < 0.4.8-1+deb11u2 | < 0.4.8-3+deb12u2 | < 0.6.1-1+deb13u2 | < 0.6.3-1

References (1)