CVEvulnerability
CVE-2026-119196
Exploitation and prioritisation
- EPSS
- 0.43% chance of exploitation in the next 30 days · in the top 63.2% of all CVEs (2026-11-03)
- EU Vulnerability Database
- EUVD-2026-113352
Affected packages
| Ecosystem | Package | Vulnerable | Fixed in | Advisory |
|---|---|---|---|---|
| PyPI | pyasn1 | < 0.6.5 | 0.6.5 | GHSA-2qm8-x737-gmw5 |
- Status
- Awaiting Analysis
- Published
- 2026-10-29
- Last modified
- 2026-10-30
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-407
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.
Related
Weakness · CWE (1)
- CWE-407 Inefficient Algorithmic Complexity weakness
Referenced by GitHub Advisory · alias (1)
- GHSA-2qm8-x737-gmw5 pyasn1 has quadratic CPU consumption in constructed BIT STRING decoding advisory · PyPI