What is CVE-2026-25479?

CVE-2026-25479 is a medium-severity vulnerability in Litestar, classified under Incorrect Regular Expression. CVSS score: 6.5/10. Published 2026-02-09.

How severe is CVE-2026-25479?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Litestar

CVE-2026-25479

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.

Published 2026-02-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.005 (38.1th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 38.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.001

Affected products

Litestar
Litestar-Org Litestar — versions < 2.20.0

Weakness classification (CWE)

CWE-185 — Incorrect Regular Expression

References

github.com/litestar-org/litestar/security/advisories/GHSA-93ph-p7v4-hwh4 (Exploit, Vendor Advisory)
github.com/litestar-org/litestar/commit/06b36f481d1bfea6f19995cfb4f203aba45c4ace (Patch)
docs.litestar.dev/2/release-notes/changelog.html (Release Notes)
github.com/litestar-org/litestar/releases/tag/v2.20.0 (Release Notes)

Frequently asked questions

What is CVE-2026-25479?: CVE-2026-25479 is a medium-severity vulnerability in Litestar, classified under Incorrect Regular Expression. CVSS score: 6.5/10. Published 2026-02-09.
How severe is CVE-2026-25479?: Medium severity. CVSS v3 base score is 6.5 out of 10.