Package vulnerability, severity high

pyasn1 has quadratic-complexity denial of service in binary REAL decoding

Published October 30, 2026, updated October 31, 2026

pyasn1 has quadratic-complexity denial of service in binary REAL decoding. Source: GHSA-mm57-4v3p-rchx (CVE-2026-119197).

What's affected

• pyasn1 (pypi)<0.6.5

What to do

1. Upgrade pyasn1 to 0.6.5 or later.

Check whether you were affected

Pharon tells teams automatically when this affects something they run. To check a machine, run this in Claude Code with the Pharon plugin, in the repository that uses it:

/pharon:check-incident ghsa-mm57-4v3p-rchx

References

• https://osv.dev/vulnerability/GHSA-mm57-4v3p-rchx
• https://github.com/pyasn1/pyasn1/security/advisories/GHSA-mm57-4v3p-rchx
• https://nvd.nist.gov/vuln/detail/CVE-2026-119197
• https://github.com/pyasn1/pyasn1/pull/132
• https://github.com/pyasn1/pyasn1/commit/ce3ec3390784780a530047e0e77be5ff457636a4
• https://github.com/pyasn1/pyasn1
• https://github.com/pyasn1/pyasn1/releases/tag/v0.6.5

Notice ghsa-mm57-4v3p-rchx, signed with key feed-prod-2026-10 (Ed25519). The Pharon CLI verifies the signature before using a notice.