# CVE-2026-119194: pyasn1: Quadratic CPU use in schemaless BER/CER/DER container decoding


- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 29 Oct 2026
- **Updated:** 29 Oct 2026

## What is CVE-2026-119194?

CVE-2026-119194 is a high-severity vulnerability in pyasn1, published on 29 Oct 2026. 

### Official description

pyasn1 is a generic ASN.1 library for Python. From 0.3.3 until 0.6.5, schemaless container decoding stores every decoded component's TagSet in a growing set even though only one-versus-multiple tag types must be distinguished. Attacker-controlled BER, CER, or DER input contains many distinct long tag IDs whose TagSet hashes collide. Each later set insertion compares against an increasing number of earlier colliding tags in ConstructedPayloadDecoderBase._decodeComponentsSchemaless, producing quadratic CPU work while decoded values and order remain valid. Repeated inputs can exhaust decoder CPU and reduce service availability. This issue is fixed in version 0.6.5.

Weakness: CWE-407 (Inefficient Algorithmic Complexity)

## Which versions are affected by CVE-2026-119194?


## How do I fix CVE-2026-119194?

No fix has been published for CVE-2026-119194 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-119194 being exploited?

There is no known exploitation of CVE-2026-119194 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-119194 and fix it if it is affected.

What it is: CVE-2026-119194 is a high-severity vulnerability in pyasn1, published on 29 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-119194 in the wild and no public exploit code.

Affected product: pyasn1. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-119194/ (Markdown: https://insights.sbomify.com/CVE-2026-119194/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-119194
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-119194
- OSV: https://osv.dev/vulnerability/CVE-2026-119194

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-119194/
Summaries are generated and may contain mistakes; the official description above is the record.