Affected: Homebrew: bilix

### Impact

Users of the python-hyper/hpack library, most commonly used as downstream dependency of the python-hyper/h2 library (an HTTP/2 client and server implementation). 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.

### Patches A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation.

### Workarounds Sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.

Affected: CleanStart: airflow-3

Security vulnerability affects the airflow-3 package. hpack is an HTTP/2 Header Encoding for Python.

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.

Affected: PyPI: hpack

### Impact

Users of the python-hyper/hpack library, most commonly used as downstream dependency of the python-hyper/h2 library (an HTTP/2 client and server implementation). 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.

### Patches A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation.

### Workarounds Sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.

Affected: openEuler:22.03-LTS-SP4: python-hpack

hpack provides a simple Python interface to the HPACK compression algorithm,used to compress HTTP headers in HTTP/2.Used by some of the most populer HTTP/2 implementations in Python,HPACK offers a great Python interface as well as optional upgrade to optimised C-based compression routines from nghttp2. Security Fix(es):

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.(CVE-2026-59980)

python313-hpack-4.2.0-1.1 on GA media

Affected: PyPI: hpack

### Impact

Users of the python-hyper/hpack library, most commonly used as downstream dependency of the python-hyper/h2 library (an HTTP/2 client and server implementation). 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.

### Patches A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation.

### Workarounds Sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.

Security update for python-hpack

Affected: Ubuntu:16.04:LTS: python-hpack, Ubuntu:18.04:LTS: python-hpack, Ubuntu:20.04:LTS: python-hpack, Ubuntu:22.04:LTS: python-hpack, Ubuntu:24.04:LTS: python-hpack, Ubuntu:26.10: python-hpack, Ubuntu:26.04:LTS: python-hpack

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.