SARA / Free Tools / CVE / CVE-2023-23603

CVE-2023-23603 — Regular expressions used to filter out forbidden properties and values from styl

Regular expressions used to filter out forbidden properties and values from style directives in calls to `console.log` weren't accounting for external URLs. Data could then be potentially exfiltrated from the browser. This vulnerability affects Firefox < 109, Firefox ESR

CVSS
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EPSS
0.16% (top 63.30%)
CWE
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Published
2023-06-02T00:00:00.000Z
Last modified
2025-12-18T15:22:57.414Z
CVSS vector
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01What is this vulnerability?

Regular expressions used to filter out forbidden properties and values from style directives in calls to `console.log` weren't accounting for external URLs. Data could then be potentially exfiltrated from the browser. This vulnerability affects Firefox < 109, Firefox ESR < 102.7, and Thunderbird < 102.7.

02Affected products

VendorProductVersions
MozillaFirefoxunspecified
MozillaFirefox ESRunspecified
MozillaThunderbirdunspecified

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

09References

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