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PatchSiren cyber security CVE debrief

CVE-2026-37737 ashleysommer CVE debrief

CVE-2026-37737 is a MEDIUM severity vulnerability in sanic-cors version 2.2.0 and prior. The vulnerability is caused by 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.

Vendor
ashleysommer
Product
sanic-cors
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-05
Original CVE updated
2026-06-05
Advisory published
2026-06-05
Advisory updated
2026-06-05

Who should care

Users of sanic-cors version 2.2.0 and prior should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The vulnerability is caused by an improper regular expression in the `try_match()` function in `sanic_cors/core.py`. The `re.match` function is used without end-anchoring, which allows an attacker to bypass CORS origin allowlists.

Defensive priority

MEDIUM

Recommended defensive actions

  • Update to a version of sanic-cors that is not vulnerable.
  • Implement proper CORS configuration to prevent unauthorized access to cross-origin requests.

Evidence notes

The vulnerability was reported in the NVD database and has a CVSS score of 6.5.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-37737 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-37737

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-37737 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-37737

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.