Assuming a controlled failed memory allocation, an attacker could have caused a use-after-free, leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Firefox ESR 115.19, Thunderbird 134, and Thunderbird 128.6.
Conclusion & alert: CVE-2025-0238 is rated Low Risk (34/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.16%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
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 | 2026-05-29 | 0.13% | 0.16% | +0.03% |
| 2 | 2026-02-15 | 0.46% | 0.13% | -0.34% |
| 3 | 2025-11-21 | — | 0.46% | — |
Full EPSS history (16 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.3 | 3.1 | MEDIUM |
|
3.9 | 1.4 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2025-0238: 3 source package rows (firefox, firefox-esr, thunderbird); 335 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 335. | https://security.alpinelinux.org/vuln/CVE-2025-0238 |
debian
|
not yet assigned | CVE-2025-0238 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-2025-0238 |
gentoo
|
high | CVE-2025-0238: 3 GLSA(s) (202501-10, 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-2025-0238 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-0238 |
suse
|
high | CVE-2025-0238 severity important: SUSE including 37 source package names (MozillaFirefox-128.6.0-112.243.1, MozillaFirefox-128.6.0-150200.152.167.1, …), 142 product×package rows across 49 product lines (Container suse/kiosk/firefox-esr, Image SLES12-SP5-SAP-Azure-LI-BYOS-Production, … (49 product lines)): Fixed 142. | https://www.suse.com/security/cve/CVE-2025-0238/ |
ubuntu
|
medium | CVE-2025-0238 medium priority: Ubuntu including 9 source packages (firefox, mozjs102, …), 65 status rows across 8 suites (bionic, focal, jammy, noble, oracular, plucky, questing, upstream): DNE 34, ignored 10, needs-triage 9, not-affected 9, released 3. | https://ubuntu.com/security/CVE-2025-0238 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| mozilla | firefox | < 115.19.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* |
| mozilla | firefox | < 134.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* |
| mozilla | firefox | >= 116.0, < 128.6.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* |
| mozilla | thunderbird | < 128.6 | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* |
| mozilla | thunderbird | >= 129.0, < 134.0 | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=1915535 | Issue Tracking Permissions Required |
| https://www.mozilla.org/security/advisories/mfsa2025-01/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-02/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-03/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-04/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-05/ | Vendor Advisory |
| https://lists.debian.org/debian-lts-announce/2025/01/msg00004.html |