The WebChannel API, which is used to transport various information across processes, did not check the sending principal but rather accepted the principal being sent. This could have led to privilege escalation attacks. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.
Conclusion & alert: CVE-2025-0237 is rated Low Risk (34.5/100): 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 | 0.12% | 0.16% | +0.04% |
| 2 | 2026-02-15 | 0.34% | 0.12% | -0.22% |
| 3 | 2025-11-04 | — | 0.34% | — |
Full EPSS history (8 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.4 | 3.1 | MEDIUM |
|
2.8 | 2.5 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2025-0237: 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-2025-0237 |
debian
|
not yet assigned | CVE-2025-0237 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-2025-0237 |
gentoo
|
high | CVE-2025-0237: 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-2025-0237 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-0237 |
suse
|
high | CVE-2025-0237 severity important: SUSE including 40 source package names (MozillaFirefox-128.6.0-112.243.1, MozillaFirefox-128.6.0-150200.152.167.1, …), 145 product×package rows across 49 product lines (Container suse/kiosk/firefox-esr, Image SLES12-SP5-SAP-Azure-LI-BYOS-Production, … (49 product lines)): Fixed 145. | https://www.suse.com/security/cve/CVE-2025-0237/ |
ubuntu
|
medium | CVE-2025-0237 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 10, not-affected 9, released 2. | https://ubuntu.com/security/CVE-2025-0237 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| mozilla | firefox | < 128.6.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* |
| mozilla | firefox | < 134.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* |
| mozilla | thunderbird | < 128.6.0 | 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=1915257 | 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/mfsa2025-04/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-05/ | Vendor Advisory |
| https://lists.debian.org/debian-lts-announce/2025/01/msg00004.html |