CVE-2026-30922
pyasn1 Vulnerable to Denial of Service via Unbounded Recursion
At a glance
- Severity
- HIGH 7.5
- EPSS
- EPSS 0.82 % · percentile 57 (2026-10-27)
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Modified
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.
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | redhat-SADP |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
Weaknesses (CWE)
Advisories
- GHSA-jr27-m4p2-rc6r — Denial of Service in pyasn1 via Unbounded Recursion
- PYSEC-2026-2263 — 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 recu
European references
- ENISA EUVD · EUVD-2026-12747
- GCVE · GCVE-0-2026-30922
CERT-FR advisories
- CERTFR-2026-AVI-1378 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1291 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1206 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1056 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0901 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0667 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0556 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0376 — Multiples vulnérabilités dans les produits Microsoft · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:pyasn1:pyasn1:*:*:*:*:*:python:*:*< 0.6.3
Affected products
| Product | Versions |
|---|---|
| pyasn1 · pyasn1 | affected < 0.6.3 |
References
- https://github.com/pyasn1/pyasn1/security/advisories/GHSA-jr27-m4p2-rc6r
- https://github.com/pyasn1/pyasn1/commit/25ad481c19fdb006e20485ef3fc2e5b3eff30ef0
- http://www.openwall.com/lists/oss-security/2026/03/20/4
- https://lists.debian.org/debian-lts-announce/2026/05/msg00001.html
- https://access.redhat.com/security/cve/CVE-2026-30922
- https://bugzilla.redhat.com/show_bug.cgi?id=2448553
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-30922.json
- https://access.redhat.com/errata/RHSA-2026:24761
- https://access.redhat.com/errata/RHSA-2026:13512
- https://access.redhat.com/errata/RHSA-2026:24762
- https://access.redhat.com/errata/RHSA-2026:13508
- https://access.redhat.com/errata/RHSA-2026:17083
- https://access.redhat.com/errata/RHSA-2026:13916
- https://access.redhat.com/errata/RHSA-2026:19138
- https://access.redhat.com/errata/RHSA-2026:12176
- https://access.redhat.com/errata/RHSA-2026:22135
- https://access.redhat.com/errata/RHSA-2026:22134
- https://access.redhat.com/errata/RHSA-2026:20588
- https://access.redhat.com/errata/RHSA-2026:22987
- https://access.redhat.com/errata/RHSA-2026:22969
- https://access.redhat.com/errata/RHSA-2026:22970
- https://access.redhat.com/errata/RHSA-2026:13917
- https://access.redhat.com/errata/RHSA-2026:19355
- https://access.redhat.com/errata/RHSA-2026:13902
- https://access.redhat.com/errata/RHSA-2026:22133
- https://access.redhat.com/errata/RHSA-2026:22132
- https://access.redhat.com/errata/RHSA-2026:22131
- https://access.redhat.com/errata/RHSA-2026:16009
- https://access.redhat.com/errata/RHSA-2026:13553
- https://access.redhat.com/errata/RHSA-2026:13545
- https://access.redhat.com/errata/RHSA-2026:6309
- https://access.redhat.com/errata/RHSA-2026:17611
- https://access.redhat.com/errata/RHSA-2026:41928
- https://access.redhat.com/errata/RHSA-2026:10184
- https://access.redhat.com/errata/RHSA-2026:65126
- https://access.redhat.com/errata/RHSA-2026:19712
- https://access.redhat.com/errata/RHSA-2026:37275
- https://access.redhat.com/errata/RHSA-2026:14020
- https://access.redhat.com/errata/RHSA-2026:6912
- https://access.redhat.com/errata/RHSA-2026:6720
- https://access.redhat.com/errata/RHSA-2026:6568
- https://access.redhat.com/errata/RHSA-2026:19375
- https://access.redhat.com/errata/RHSA-2026:6926
- https://access.redhat.com/errata/RHSA-2026:8437
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |