CVE-2026-25479
MEDIUMLitestar < 2.20.0 - Host Validation Bypass via Regex Metacharacter Injection
Title source: llmDescription
Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. Prior to 2.20.0, in litestar.middleware.allowed_hosts, allowlist entries are compiled into regex patterns in a way that allows regex metacharacters to retain special meaning (e.g., . matches any character). This enables a bypass where an attacker supplies a host that matches the regex but is not the intended literal hostname. This vulnerability is fixed in 2.20.0.
References (4)
Core 4
Core References
Exploit, Vendor Advisory x_refsource_confirm
https://github.com/litestar-org/litestar/security/advisories/GHSA-93ph-p7v4-hwh4
Patch x_refsource_misc
https://github.com/litestar-org/litestar/commit/06b36f481d1bfea6f19995cfb4f203aba45c4ace
Release Notes x_refsource_misc
https://docs.litestar.dev/2/release-notes/changelog.html#2.20.0
Release Notes x_refsource_misc
https://github.com/litestar-org/litestar/releases/tag/v2.20.0
Scores
CVSS v3
6.5
EPSS
0.0002
EPSS Percentile
5.4%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-185
Status
published
Products (2)
litestar/litestar
< 2.20.0
pypi/litestar
2.19.0 - 2.20.0PyPI
Published
Feb 09, 2026
Tracked Since
Feb 18, 2026