# CVE-2026-25479: Litestar's AllowedHosts has a validation bypass due to unescaped regex metacharacters in configured host patterns

Source: https://junglewise.ai/threats/cve-2026-25479-litestar-s-allowedhosts-has-a-validation-bypass-due-to-unescaped  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-02-09  
License: CC BY 4.0 with a link back

CVE-2026-25479 · Severity: low · CVSS 3.1 · Published 2026-02-09

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.

Technologies: [litestar (PyPI)](https://junglewise.ai/threats/technologies/litestar). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-25479 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-25479 being exploited in the wild.

**How severe is CVE-2026-25479?** Low severity, with a CVSS score of 3.1, published 9 February 2026.

**Which products and versions are affected?** litestar (PyPI) ECOSYSTEM:introduced=0,fixed=2.20.0, ECOSYSTEM:introduced=2.19.0,fixed=2.20.0.

**Is there a fix for CVE-2026-25479?** Yes. litestar (PyPI): upgrade to 2.20.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-25479?** Check whether you run litestar (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- litestar (PyPI): upgrade to 2.20.0 or later

  ```sh
  pip install "litestar>=2.20.0"
  ```


## Affected products

- litestar (PyPI) ECOSYSTEM:introduced=0,fixed=2.20.0, ECOSYSTEM:introduced=2.19.0,fixed=2.20.0

## Identifiers

- CVE-2026-25479
- GHSA-93ph-p7v4-hwh4
- PYSEC-2026-2196

## Related threats

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