CVE-2026-119196: pyasn1 · Inefficient Algorithmic Complexity
Affects pyasn1Source CVE Database V5
Not known to be exploited · CVSS 7.5 High : upgrade to 0.6.5 soon.
Data as of 29 Oct 2026, 20:00 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 29 Oct 2026.
What to do
Upgrade pyasn1 to 0.6.5.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| pyasn1pyasn1 | Affected
| Fixed in
|
PyPIpyasn1pkg:pypi/pyasn1Other threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade pyasn1 to version 0.6.5 or later, where this inefficient algorithmic complexity issue is fixed. No other mitigations are indicated or required.
Description
CVE-2026-119196 is a high-severity vulnerability in the pyasn1 Python library prior to version 0.6.5. It involves inefficient algorithmic complexity during decoding of constructed BIT STRING values, where repeated shifting and copying of accumulated bit values causes quadratic CPU workload. This can lead to CPU exhaustion when processing large fragmented BIT STRING inputs. The issue is fixed in pyasn1 version 0.6.5.