CVE-2026-16360: Memory safety bugs present in Firefox ESR 115.37, Firefox ESR 140.12 and Firefox 152. Some of these bugs showed evidence of memory corruption and we presume that with enough effort

criticalCVSS 9.8CVE-2026-16360

Memory safety bugs present in Firefox ESR 115.37, Firefox ESR 140.12 and Firefox 152. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: critical — CVSS 9.8
Published: 2026-07-21
Last updated: 2026-07-24
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-16360

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-163600.33% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 25% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-16360	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[NEW] [high] Mozilla Firefox and Firefox ESR: Multiple vulnerabilitiescert-bund
unknownMultiple vulnerabilities in Mozilla Thunderbird (July 23, 2026)cert-fr-avis
unknownMozilla Products Multiple Vulnerabilitieshkcert
unknownMultiple vulnerabilities in Mozilla products (July 22, 2026)cert-fr-avis
unknownDSA-6394-1 firefox-esr - security updatedebian

Recent advisories for Memory safety bugs

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

criticalCVE-2026-16412: Memory safety bugs present in Firefox ESR 140.12 and Firefox 152. Some of these bugs showed ev…nvd · 2026-07-21
criticalCVE-2026-16411: Memory safety bugs present in Firefox 152. Some of these bugs showed evidence of memory corrup…nvd · 2026-07-21
criticalCVE-2026-16361: Memory safety bugs present in Thunderbird ESR 140.12. Some of these bugs showed evidence of me…nvd · 2026-07-21
criticalCVE-2026-14241: Memory safety bugs present in Firefox 152.0.3. Some of these bugs showed evidence of memory co…nvd · 2026-06-30