7.5

CVE-2026-119196: pyasn1: Quadratic CPU consumption in constructed BIT STRING decoding

Awaiting analysis
AliasesDEBIAN-CVE-2026-119196GHSA-2qm8-x737-gmw5UBUNTU-CVE-2026-119196
Published 29-10-2026Last modified 29-10-2026

Vulnerability summary

CVE-2026-119196 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.

Description

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.5, constructed BIT STRING decoding repeatedly shifts and copies the complete bit value accumulated from earlier fragments. Attacker-controlled BER or CER input contains many constructed BIT STRING fragments; schema-driven DER also accepts a definite-length constructed BIT STRING. BitStringPayloadDecoder repeatedly calls BitString.fromOctetString with the prior bitString as prepend, shifting an ever-growing SizedInteger for each fragment and causing quadratic work. Large fragmented values can exhaust CPU during decode() without requiring later conversion or formatting. 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.

Chainguard48 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-bigqueryAll versions (No fix recorded) | < 1.10.3-r13
  • elastic-connectors-8.19All versions (No fix recorded) | < 8.19.23-r8
Wolfi3 products
  • kubeflow-pipelines-apiserverAll versions (No fix recorded) | < 2.18.0-r1
  • 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< 0.6.5
Ubuntu1 product
  • pyasn1All versions (No fix recorded)

6 vendors · 55 products

References

10 links