Nixpkgs security tracker
Untriaged
Permalink
CVE-2026-54340
7.5 HIGH
- CVSS version (CVSS): 3.1
- Attack Vector (AV): Network (N)
- Attack Complexity (AC): Low (L)
- Privileges Required (PR): None (N)
- User Interaction (UI): None (N)
- Scope (S): Unchanged (U)
- Confidentiality (C): None (N)
- Integrity (I): None (N)
- Availability (A): High (H)
- Modified Attack Vector (MAV): Network (N)
- Modified Attack Complexity (MAC): Low (L)
- Modified Privileges Required (MPR): None (N)
- Modified User Interaction (MUI): None (N)
- Modified Confidentiality (MC): None (N)
- Modified Scope (MS): Unchanged (U)
- Modified Integrity (MI): None (N)
- Modified Availability (MA): High (H)
Activity log
- Created suggestion
h2o has HTTP/2 state amplification
h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. Prior to commit 9265bdd, there is an HTTP/2 state amplification issue that combines HPACK decompression amplification with Slowloris-style stream stalling. Amplified decoded header state can be retained by stalled HTTP/2 streams, and depending on the configuration, additional limits are needed to bound decoded header state and prevent attack. This issue has been fixed by commit 9265bdd.
References
-
https://github.com/h2o/h2o/security/advisories/GHSA-qcrr-wrhc-pgq9 x_refsource_CONFIRM
Affected products
h2o
- ==< 9265bdd
Matching in nixpkgs
pkgs.h2o
Optimized HTTP/1.x, HTTP/2, HTTP/3 server
-
nixos-unstable -
- nixos-unstable-small 2.3.0-rolling-2026-06-29
-
nixos-26.05 -
- nixos-26.05-small 2.3.0-rolling-2026-05-15
Package maintainers
-
@thoughtpolice Austin Seipp <aseipp@pobox.com>
-
@toastal toastal <toastal+nix@posteo.net>