CVE catalog
CVE-2026-59885
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER, CER, and DER decoders process OBJECT IDENTIFIER and RELATIVE-OID values in quadratic time relative to the number of arcs, so a sm
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.62% · Oct 25, 2026
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER, CER, and DER decoders process OBJECT IDENTIFIER and RELATIVE-OID values in quadratic time relative to the number of arcs, so a small crafted payload containing an OID with many arcs consumes excessive CPU per decode() call and can deny service to applications that decode untrusted ASN.1 data. The corresponding encoders have the same quadratic behavior when an application re-encodes previously decoded attacker-supplied values. This issue is fixed in version 0.6.4.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | pyasn1 | sid | 0.6.4-1 | fixed |
| Debian | pyasn1 | forky | 0.6.4-1 | fixed |
| Debian | pyasn1 | trixie | 0.6.1-1+deb13u3 | fixed |
| Debian | pyasn1 | trixie-security | 0.6.1-1+deb13u2 | vulnerable |
| Debian | pyasn1 | bookworm | 0.4.8-3+deb12u2 | vulnerable |
| Debian | pyasn1 | bookworm-security | 0.4.8-3+deb12u3 | fixed |
| Cpe | pyasn1 | Not reported | Not reported | vulnerable |
| Pip | pyasn1 | Not reported | 0.6.4 | fixed |
| PyPI | pyasn1 | Not reported | 0.6.4 | fixed |
| Ubuntu | pyasn1 | noble | 0.4.8-4ubuntu0.3 | fixed |
| Ubuntu | python-pyasn1-doc | noble | 0.4.8-4ubuntu0.3 | fixed |
| Ubuntu | python3-pyasn1 | noble | 0.4.8-4ubuntu0.3 | fixed |
| Ubuntu | pyasn1 | pro | 0.4.2-3 | vulnerable |
| Ubuntu | pyasn1 | pro | 0.4.2-3build1 | vulnerable |
| Ubuntu | pyasn1 | pro | 0.4.2-3ubuntu0.20.04.1~esm1 | vulnerable |
| Ubuntu | pyasn1 | 22.04 | 0.4.8-1 | vulnerable |
| Ubuntu | pyasn1 | 22.04 | 0.4.8-1ubuntu0.1 | vulnerable |
| Ubuntu | pyasn1 | 22.04 | 0.4.8-1ubuntu0.2 | vulnerable |
| Ubuntu | pyasn1 | 22.04 | 0.4.8-1ubuntu0.3 | fixed |
| Ubuntu | pyasn1 | 24.04 | 0.4.8-4 | vulnerable |
| Ubuntu | pyasn1 | 24.04 | 0.4.8-4ubuntu0.1 | vulnerable |
| Ubuntu | pyasn1 | 24.04 | 0.4.8-4ubuntu0.2 | vulnerable |
| Ubuntu | pyasn1 | 24.04 | 0.4.8-4ubuntu0.3 | fixed |
| Ubuntu | pyasn1 | 26.04 | 0.6.1-1 | vulnerable |
| Ubuntu | pyasn1 | 26.04 | 0.6.1-1build1 | vulnerable |
| Ubuntu | pyasn1 | 26.04 | 0.6.2-1 | vulnerable |
| Ubuntu | pyasn1 | 26.04 | 0.6.3-1 | vulnerable |
| Ubuntu | pyasn1 | 26.04 | 0.6.3-1ubuntu0.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | pyasn1 | source | sid | 0.6.4-1 | not yet assigned | Not reported | [1142388] |
| Debian | pyasn1 | source | forky | 0.6.4-1 | not yet assigned | Not reported | [1142388] |
| Debian | pyasn1 | source | trixie | 0.6.1-1+deb13u3 | not yet assigned | Not reported | [1142388] |
| Debian | pyasn1 | source | bookworm | 0.4.8-3+deb12u3 | not yet assigned | Not reported | [1142388] |
| Pip | pyasn1 | pip | Not reported | 0.6.4 | Not reported | Not reported | Not reported |
| PyPI | pyasn1 | PyPI | Not reported | 0.6.4 | Not reported | GHSA-8PPF-4F7H-5PPJ | Not reported |
| Ubuntu | pyasn1 | deb | noble | 0.4.8-4ubuntu0.3 | Not reported | Not reported | Not reported |
| Ubuntu | python-pyasn1-doc | deb | noble | 0.4.8-4ubuntu0.3 | Not reported | Not reported | Not reported |
| Ubuntu | python3-pyasn1 | deb | noble | 0.4.8-4ubuntu0.3 | Not reported | Not reported | Not reported |
| Ubuntu | pyasn1 | deb | 22.04 | 0.4.8-1ubuntu0.3 | Not reported | UBUNTU-CVE-2026-59885 | Not reported |
| Ubuntu | pyasn1 | deb | 24.04 | 0.4.8-4ubuntu0.3 | Not reported | UBUNTU-CVE-2026-59885 | Not reported |
| Ubuntu | pyasn1 | deb | 26.04 | 0.6.3-1ubuntu0.1 | Not reported | UBUNTU-CVE-2026-59885 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [python3-pyasn1]Affected
Source package: [pyasn1]
Details (4)
0.4.8-3+deb12u2· all · bookwormAffected · Fixed:
0.4.8-3+deb12u3nvd · pyasn1 · debian · bookworm; nvd · pyasn1 · debian · 12
0.4.8-3+deb12u2· all · bookwormAffected · Fixed:
0.4.8-3+deb12u3nvd · pyasn1 · debian · bookworm; nvd · pyasn1 · debian · 12
0.4.8-3+deb12u2· all · bookworm-securityAffected · Fixed:
0.4.8-3+deb12u3nvd · pyasn1 · debian · bookworm; nvd · pyasn1 · debian · 12
0.4.8-3+deb12u2· all · bookworm-securityAffected · Fixed:
0.4.8-3+deb12u3nvd · pyasn1 · debian · bookworm; nvd · pyasn1 · debian · 12
- [python-pyasn1-doc]Affected
Source package: [pyasn1]
Details (4)
0.4.8-3+deb12u2· all · bookwormAffected · Fixed:
0.4.8-3+deb12u3nvd · pyasn1 · debian · bookworm; nvd · pyasn1 · debian · 12
0.4.8-3+deb12u2· all · bookwormAffected · Fixed:
0.4.8-3+deb12u3nvd · pyasn1 · debian · bookworm; nvd · pyasn1 · debian · 12
0.4.8-3+deb12u2· all · bookworm-securityAffected · Fixed:
0.4.8-3+deb12u3nvd · pyasn1 · debian · bookworm; nvd · pyasn1 · debian · 12
0.4.8-3+deb12u2· all · bookworm-securityAffected · Fixed:
0.4.8-3+deb12u3nvd · pyasn1 · debian · bookworm; nvd · pyasn1 · debian · 12
[Debian 13 (Trixie)]
- [python3-pyasn1]Affected
Source package: [pyasn1]
Details (6)
0.6.1-1+deb13u2· all · trixieAffected · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
0.6.1-1+deb13u2· all · trixieAffected · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
0.6.4-1~bpo13+1· all · trixie-backportsFixed · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
0.6.4-1~bpo13+1· all · trixie-backportsFixed · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
0.6.1-1+deb13u2· all · trixie-securityAffected · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
0.6.1-1+deb13u2· all · trixie-securityAffected · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
- [python-pyasn1-doc]Affected
Source package: [pyasn1]
Details (6)
0.6.1-1+deb13u2· all · trixieAffected · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
0.6.1-1+deb13u2· all · trixieAffected · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
0.6.4-1~bpo13+1· all · trixie-backportsFixed · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
0.6.4-1~bpo13+1· all · trixie-backportsFixed · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
0.6.1-1+deb13u2· all · trixie-securityAffected · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
0.6.1-1+deb13u2· all · trixie-securityAffected · Fixed:
0.6.1-1+deb13u3nvd · pyasn1 · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_11318-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-59885]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-59885]
- [https://osv.dev/vulnerability/GHSA-8ppf-4f7h-5ppj]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-59885]
- [https://security-tracker.debian.org/tracker/CVE-2026-59885]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-59885.json]
- [https://ubuntu.com/security/notices/USN-8712-1]
[Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]