CVE catalog

CVE-2024-25622

h2o: CVE-2024-25622

Severity: Medium
Published: Oct 11, 2024, 3:15:00 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.46% · Oct 25, 2026

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. The configuration directives provided by the headers handler allows users to modify the response headers being sent by h2o. The configuration file of h2o has scopes, and the inner scopes (e.g., path level) are expected to inherit the configuration defined in outer scopes (e.g., global level). However, if a header directive is used in the inner scope, all the definition in outer scopes are ignored. This can lead to headers not being modified as expected. Depending on the headers being added or removed unexpectedly, this behavior could lead to unexpected client behavior. This vulnerability is fixed in commit 123f5e2b65dcdba8f7ef659a00d24bd1249141be.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	h2o	bookworm	`2.2.5+dfsg2-7`	vulnerable
Ubuntu	h2o	pro	`2.2.5+dfsg2-6`	vulnerable
Ubuntu	h2o	pro	`2.2.5+dfsg2-6.1`	vulnerable
Ubuntu	h2o	pro	`2.2.5+dfsg2-6.1ubuntu1`	vulnerable
Ubuntu	h2o	pro	`2.2.5+dfsg2-6.1ubuntu2`	vulnerable
Ubuntu	h2o	pro	`2.2.5+dfsg2-6.1ubuntu2+esm1`	vulnerable
Ubuntu	h2o	24.04	`2.2.5+dfsg2-7`	vulnerable
Ubuntu	h2o	24.04	`2.2.5+dfsg2-8`	vulnerable
Ubuntu	h2o	24.04	`2.2.5+dfsg2-8.1ubuntu1`	vulnerable
Ubuntu	h2o	24.04	`2.2.5+dfsg2-8.1ubuntu2`	vulnerable
Ubuntu	h2o	24.04	`2.2.5+dfsg2-8.1ubuntu3`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	h2o	source	bookworm	`(unfixed)`	not yet assigned	Not reported	[1084984]

[Debian bug #1084984]

Notes

[bookworm] h2o: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[h2o]Affected
Details (2)
- 2.2.5+dfsg2-7 · amd64 · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
- 2.2.5+dfsg2-7 · arm64 · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
[h2o-doc]Affected
Source package: [h2o]
Details (2)
- 2.2.5+dfsg2-7 · all · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
- 2.2.5+dfsg2-7 · all · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
[libh2o0.13]Affected
Source package: [h2o]
Details (2)
- 2.2.5+dfsg2-7 · amd64 · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
- 2.2.5+dfsg2-7 · arm64 · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
[libh2o-dev]Affected
Source package: [h2o]
Details (2)
- 2.2.5+dfsg2-7 · amd64 · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
- 2.2.5+dfsg2-7 · arm64 · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
[libh2o-dev-common]Affected
Source package: [h2o]
Details (2)
- 2.2.5+dfsg2-7 · all · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
- 2.2.5+dfsg2-7 · all · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
[libh2o-evloop0.13]Affected
Source package: [h2o]
Details (2)
- 2.2.5+dfsg2-7 · amd64 · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
- 2.2.5+dfsg2-7 · arm64 · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
[libh2o-evloop-dev]Affected
Source package: [h2o]
Details (2)
- 2.2.5+dfsg2-7 · amd64 · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12
- 2.2.5+dfsg2-7 · arm64 · bookworm
  Affected
  dsa · h2o · debian · bookworm; dsa · h2o · debian · 12

Observed: Oct 27, 2026, 1:32:50 AM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database]