# What changed in pyasn1

> 11 changes in pyasn1 0.6 from its official release notes, upgrade guides and advisories: 1 breaking, 6 security. Each one cited. Sources checked 2026-10-21. HTML: https://unstale.sh/pypi/pyasn1/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## pyasn1 0.6

### Breaking changes

- The ASN.1 decoder now limits nesting depth to prevent stack overflow from deeply nested structures. (0.6.3) — [release notes](https://github.com/pyasn1/pyasn1/releases/tag/v0.6.3)

### Security

- pyasn1 BER/CER/DER decoder denial of service via unbounded long-form tag IDs (0.6.4) — [security advisory](https://github.com/advisories/GHSA-M4P7-R5RC-7G4J), [release notes](https://github.com/pyasn1/pyasn1/releases/tag/v0.6.4)
- pyasn1: Quadratic complexity in OBJECT IDENTIFIER and RELATIVE-OID processing allows denial of service (0.6.4) — [security advisory](https://github.com/advisories/GHSA-8PPF-4F7H-5PPJ), [release notes](https://github.com/pyasn1/pyasn1/releases/tag/v0.6.4)
- pyasn1: Uncontrolled resource consumption when converting decoded REAL values (0.6.4) — [security advisory](https://github.com/advisories/GHSA-HM4W-WWCW-MR6R), [release notes](https://github.com/pyasn1/pyasn1/releases/tag/v0.6.4)
- Denial of Service in pyasn1 via Unbounded Recursion (0.6.3) — [security advisory](https://github.com/advisories/GHSA-JR27-M4P2-RC6R)
- Fixed continuation octet limits in the decoder, addressing CVE-2026-23490. (0.6.2) — [release notes](https://github.com/pyasn1/pyasn1/releases/tag/v0.6.2)
- pyasn1 has a DoS vulnerability in decoder (0.6.2) — [security advisory](https://github.com/advisories/GHSA-63VM-454H-VHHQ)

### Fixes and other changes

- Fixed incorrect parsing of fractional seconds. (0.6.3) — [release notes](https://github.com/pyasn1/pyasn1/releases/tag/v0.6.3)
- Fixed OverflowError caused by an oversized BER length field. (0.6.3) — [release notes](https://github.com/pyasn1/pyasn1/releases/tag/v0.6.3)
- Fixed the stacklevel used for DeprecationWarning from deprecated attributes. (0.6.3) — [release notes](https://github.com/pyasn1/pyasn1/releases/tag/v0.6.3)
- Added support for Python 3.14. (0.6.2) — [release notes](https://github.com/pyasn1/pyasn1/releases/tag/v0.6.2)