CVE-2026-37737: sanic-cors · Permissive Regular Expression
Affects sanic-corsSource CVE Database V5
Not known to be exploited · CVSS 6.5 Medium.
Data as of 26 Oct 2026, 16:39 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 5 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
PyPIsanic-corspkg:pypi/sanic-corsOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until an official fix is available, users should consider additional manual validation of CORS origins or implement alternative controls to restrict cross-origin access. Monitor vendor channels for updates regarding patches or official mitigations.
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.
References
- github.com/ashleysommer/sanic-cors/blob/master/sanic_cors/core.py (opens in a new tab)
- github.com/ashleysommer/sanic-cors (opens in a new tab)
- pypi.org/project/Sanic-Cors/ (opens in a new tab)
- github.com/npbhatter17/security-advisories/blob/main/CVE-2026-37737-sanic-cors-advisory.md (opens in a new tab)