SARA / Free Tools / CVE / CVE-2023-4577

CVE-2023-4577 — When `UpdateRegExpStatics` attempted to access `initialStringHeap` it could alre

When `UpdateRegExpStatics` attempted to access `initialStringHeap` it could already have been garbage collected prior to entering the function, which could potentially have led to an exploitable crash. This vulnerability affects Firefox < 117, Firefox ESR < 115.2, and Thund

CVSS
— —
EPSS
0.10% (top 72.10%)
CWE
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Published
2023-09-11T08:01:02.684Z
Last modified
2025-12-18T15:23:09.123Z
CVSS vector
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01What is this vulnerability?

When `UpdateRegExpStatics` attempted to access `initialStringHeap` it could already have been garbage collected prior to entering the function, which could potentially have led to an exploitable crash. This vulnerability affects Firefox < 117, Firefox ESR < 115.2, and Thunderbird < 115.2.

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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