CVE-2026-119196: Ansible@9 · pyasn1 has quadratic CPU consumption in constructed BIT STRING decoding
Affects ansible@9Source GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.5 High.
Data as of 31 Oct 2026, 17:21 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 7.5 |
|---|
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 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewansible@9pkg:brew/ansible%409Other 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
Mitigation involves ensuring that untrusted ASN.1 input does not reach the vulnerable decoder paths or limiting input size and fragment count to prevent CPU exhaustion. Applications should consider applying input validation or rate limiting to reduce exposure. Monitor vendor channels for updates or patches addressing this issue.
Description
A vulnerability in pyasn1 versions up to 0.6.4 causes quadratic CPU consumption when decoding constructed BIT STRING values with many fragments. This can lead to CPU exhaustion and denial of service if attacker-controlled ASN.1 data is decoded. The issue affects BER and CER decoders and certain schema-driven DER decoding paths. The vulnerability does not impact confidentiality or integrity but can cause service disruption.
References
- github.com/pyasn1/pyasn1/security/advisories/GHSA-2qm8-x737-gmw5 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-119196 (opens in a new tab)
- github.com/pyasn1/pyasn1/pull/132 (opens in a new tab)
- github.com/pyasn1/pyasn1/commit/73ba7b043cc7e92cb37f16f2c955bff93b0e6f6c (opens in a new tab)
- github.com/pyasn1/pyasn1 (opens in a new tab)
- github.com/pyasn1/pyasn1/releases/tag/v0.6.5 (opens in a new tab)