CVE-2026-37737 sanic-cors contains an improper regular expression in the try_match() function
Attackers can bypass CORS origin allowlists via improper regex matching, gaining unauthorized access to authenticated cross-origin resources.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-37737?
CVE-2026-37737 is a medium-severity vulnerability in n/a, published on 5 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2026-37737?
3 open source packages ship an affected version, including sanic-cors.
| Package | Affected | Fixed in |
|---|---|---|
sanic-cors PyPI | All versions to 2.2.0 | None |
sanic-cors PyPI | All versions to 2.2.0 | None |
sanic-cors PyPI | All versions to 2.2.0 | None |
How do I fix CVE-2026-37737?
No fix has been published for CVE-2026-37737 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-37737 being exploited?
There is no known exploitation of CVE-2026-37737 in the wild and no public exploit code.
Sources
Also known as GHSA-94jw-hqvj-vw74, PYSEC-2026-3539.