Memory safety bugs present in Firefox 136, Thunderbird 136, Firefox ESR 128.8, and Thunderbird 128.8. 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 137, Firefox ESR 128.9, Thunderbird 137, and Thunderbird 128.9.
Conclusion & alert: CVE-2025-3030 is rated Moderate Risk (50.7/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.28%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-12 | 0.24% | 0.28% | +0.05% |
| 2 | 2026-05-10 | 0.44% | 0.24% | -0.20% |
| 3 | 2026-01-26 | — | 0.44% | — |
Full EPSS history (7 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.1 | 3.1 | HIGH |
|
2.2 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2025-3030: 3 source package rows (firefox, firefox-esr, thunderbird); 349 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 349. | https://security.alpinelinux.org/vuln/CVE-2025-3030 |
debian
|
not yet assigned | CVE-2025-3030 not yet assigned priority: Debian including 3 source packages (firefox, firefox-esr, thunderbird), 11 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 11. | https://security-tracker.debian.org/tracker/CVE-2025-3030 |
gentoo
|
high | CVE-2025-3030: 3 GLSA(s) (202505-02, 202505-03, 202509-02), 5 atom(s) (dev-lang/spidermonkey, mail-client/thunderbird, mail-client/thunderbird-bin, www-client/firefox, www-client/firefox-bin); latest impact high. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2025-3030 |
redhat
|
high | — | https://access.redhat.com/security/cve/CVE-2025-3030 |
suse
|
high | CVE-2025-3030 severity important: SUSE including 37 source package names (MozillaFirefox-128.9.0-112.252.1, MozillaFirefox-128.9.0-150200.152.176.1, …), 127 product×package rows across 44 product lines (Container suse/kiosk/firefox-esr, Image SLES12-SP5-SAP-Azure-LI-BYOS-Production, … (44 product lines)): Fixed 127. | https://www.suse.com/security/cve/CVE-2025-3030/ |
ubuntu
|
medium | CVE-2025-3030 medium priority: Ubuntu including 9 source packages (firefox, mozjs102, …), 65 status rows across 8 suites (bionic, focal, jammy, noble, oracular, plucky, questing, upstream): DNE 35, ignored 10, not-affected 9, needs-triage 8, released 3. | https://ubuntu.com/security/CVE-2025-3030 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| mozilla | firefox | < 128.8.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* |
| mozilla | firefox | < 136.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* |
| mozilla | thunderbird | < 128.8.0 | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* |
| mozilla | thunderbird | >= 129.0, < 136.0 | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://bugzilla.mozilla.org/buglist.cgi?bug_id=1850615%2C1932468%2C1942551%2C1951017%2C1951494 | Broken Link Issue Tracking |
| https://www.mozilla.org/security/advisories/mfsa2025-20/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-22/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-23/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-24/ | Vendor Advisory |
| https://lists.debian.org/debian-lts-announce/2025/04/msg00005.html |