Hi,

The following vulnerability was published for python-hpack.

CVE-2026-59980[0]:
| hpack is an HTTP/2 Header Encoding for Python. Prior to version
| 4.2.0, unbounded variable integer decoding can cause run-away
| computation on malformed input leading to O(n^2) runtime,
| effectively blocking further processing with large enough
| unsanitized input. A fix is available in python-hyper/hpack v4.2.0
| to restricted variable integer decoding to uint32 to prevent run-
| away computation. As a workaround, sanitize input to hpack decoder
| for long sequences of `0xFF` values to prevent malicious use.


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2026-59980
https://www.cve.org/CVERecord?id=CVE-2026-59980
[1] https://github.com/python-hyper/hpack/security/advisories/GHSA-8v8h-hg4w-mvq2
[2] https://github.com/python-hyper/hpack/commit/8cfb02c547740e16dbfe7aba77bad84b297cec2c

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore