Medium severity · published Feb 9, 2026
CVE-2026-25479
Litestar has an AllowedHosts validation bypass due to unescaped regex metacharacters in configured host patterns
6.5
CVSS
0.4%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 29% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
litestar · litestar-org
< 2.20.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25479
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-25479
Release Notes
https://docs.litestar.dev/2/release-notes/changelog.html#2.20.0
Patch
https://github.com/litestar-org/litestar/commit/06b36f481d1bfea6f19995cfb4f203aba45c4ace
Release Notes
https://github.com/litestar-org/litestar/releases/tag/v2.20.0
Exploit
https://github.com/litestar-org/litestar/security/advisories/GHSA-93ph-p7v4-hwh4
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