CVE-2026-119196: pyasn1 is a generic ASN.1 library for Python
Affects pyasn1Source GCVE Database
Not known to be exploited · CVSS 7.5 High · fixed in 0.6.5 : patch pyasn1 soon.
Data as of 5 Nov 2026, 12:35 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 7.5 |
|---|
- Patch
- Available – fixed in 0.6.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 29 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10pyasn1pkg:deb/ubuntu/pyasn1?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSpyasn1pkg:deb/ubuntu/pyasn1?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSpyasn1pkg:deb/ubuntu/pyasn1?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSpyasn1pkg:deb/ubuntu/pyasn1?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 20.04 LTSpyasn1pkg:deb/ubuntu/pyasn1?arch=source&distro=esm-infra/focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTSpyasn1pkg:deb/ubuntu/pyasn1?arch=source&distro=esm-infra/bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2026-119196 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-119196 (opens in a new tab)
- github.com/pyasn1/pyasn1/commit/73ba7b043cc7e92cb37f16f2c955bff93b0e6f6c (opens in a new tab)
- github.com/pyasn1/pyasn1/pull/132 (opens in a new tab)
- github.com/pyasn1/pyasn1/releases/tag/v0.6.5 (opens in a new tab)
- github.com/pyasn1/pyasn1/security/advisories/GHSA-2qm8-x737-gmw5 (opens in a new tab)