7.5

CVE-2026-119194: pyasn1: Quadratic CPU use in schemaless BER/CER/DER container decoding

Awaiting analysis
AliasesDEBIAN-CVE-2026-119194GHSA-fm9c-5rcf-2q5pUBUNTU-CVE-2026-119194
Published 29-10-2026Last modified 03-11-2026

Vulnerability summary

CVE-2026-119194 is a high (CVSS 7.5) Inefficient Algorithmic Complexity vulnerability in pyasn1. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.8% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.43%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 29-10-2026
    PublishedVulnerability first disclosed.
  2. 03-11-2026
    Last modifiedVulnerability information updated.

Description

pyasn1 is a generic ASN.1 library for Python. From 0.3.3 until 0.6.5, schemaless container decoding stores every decoded component's TagSet in a growing set even though only one-versus-multiple tag types must be distinguished. Attacker-controlled BER, CER, or DER input contains many distinct long tag IDs whose TagSet hashes collide. Each later set insertion compares against an increasing number of earlier colliding tags in ConstructedPayloadDecoderBase._decodeComponentsSchemaless, producing quadratic CPU work while decoded values and order remain valid. Repeated inputs can exhaust decoder CPU and reduce service availability. This issue is fixed in version 0.6.5.

CVSS metrics

7 scores · 7 sources · 1 version

EPSS trend

Probability

0.43%

Chance of exploitation in the next 30 days

Percentile

37%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

30-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard51 products
  • airflow-2All versions (No fix recorded)
  • aws-cli-1All versions (No fix recorded) | < 1.46.2-r1
  • barmanAll versions (No fix recorded) | < 3.20.1-r3
  • dbt-bigquery< 1.10.3-r13
  • elastic-connectors-8.19All versions (No fix recorded) | < 8.19.23-r8
Wolfi4 products
  • kubeflow-pipelines-apiserverAll versions (No fix recorded) | < 2.18.0-r1
  • kubeflow-pipelines-visualization-serverAll versions (No fix recorded)
  • superset-6.0All versions (No fix recorded)
  • superset-6.1All versions (No fix recorded) | < 6.1.0-r24
Debian1 product
  • pyasn1All versions (No fix recorded) | < 0.6.5-1
Pyasn11 product
PyPI1 product
  • pyasn1≥ 0.3.3, < 0.6.5
Ubuntu1 product
  • pyasn1All versions (No fix recorded)

6 vendors · 59 products

References

10 links