CVE-2026-23490 | pyasn1 has a DoS vulnerability in decoder

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.2, a Denial-of-Service issue has been found that leads to memory exhaustion from malformed RELATIVE-OID with excessive continuation octets. This vulnerability is fixed in 0.6.2.

Published: 2026-01-16 Last update: 2026-03-13 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-23490 is rated Low Risk (31.6/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-23490

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-18 0.05% 0.02% -0.03%
2 2026-01-22 0.04% 0.05% +0.01%
3 2026-01-17 — 0.04% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-23490

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-23490

GitHub Security Advisory for CVE-2026-23490

GHSA-63vm-454h-vhhq · Severity: high · Ecosystem: pip — pyasn1 has a DoS vulnerability in decoder

OS Trackers for CVE-2026-23490

vendor priority summary link
debian not yet assigned CVE-2026-23490 not yet assigned priority: Debian including 1 source packages (pyasn1), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-23490
redhat high — https://access.redhat.com/security/cve/CVE-2026-23490
suse high — https://www.suse.com/security/cve/CVE-2026-23490/
ubuntu medium CVE-2026-23490 medium priority: Ubuntu including 1 source packages (pyasn1), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): released 8. https://ubuntu.com/security/CVE-2026-23490

Affected software / configurations for CVE-2026-23490

Vendor Product Version Raw CPE
pyasn1 pyasn1 < 0.6.2 cpe:2.3:a:pyasn1:pyasn1:*:*:*:*:*:python:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References for CVE-2026-23490

cvelogic Threat Intelligence