Using a redirect embedded into <code>sourceMappingUrls</code> could allow for navigation to external protocol links in sandboxed iframes without <code>allow-top-navigation-to-custom-protocols</code>. This vulnerability affects Firefox for Android < 112, Firefox < 112, and Focus for Android < 112.
Conclusion & alert: CVE-2023-29540 is rated Low Risk (37.4/100): 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 | 2026-05-31 | 0.14% | 0.16% | +0.02% |
| 2 | 2026-04-26 | 0.17% | 0.14% | -0.03% |
| 3 | 2026-02-25 | — | 0.17% | — |
Full EPSS history (5 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.1 | 3.1 | MEDIUM |
|
2.8 | 2.7 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
medium | CVE-2023-29540: 1 source package rows (firefox); 74 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 74. | https://security.alpinelinux.org/vuln/CVE-2023-29540 |
debian
|
not yet assigned | CVE-2023-29540 not yet assigned priority: Debian including 1 source packages (firefox), 1 status rows across 1 suites (sid): resolved 1. | https://security-tracker.debian.org/tracker/CVE-2023-29540 |
gentoo
|
high | CVE-2023-29540: 1 GLSA(s) (202305-35), 2 atom(s) (www-client/firefox, www-client/firefox-bin); latest impact high. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-29540 |
ubuntu
|
medium | CVE-2023-29540 medium priority: Ubuntu including 7 source packages (firefox, mozjs38, …), 70 status rows across 10 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): DNE 38, ignored 19, not-affected 9, released 3, needs-triage 1. | https://ubuntu.com/security/CVE-2023-29540 |
| URL | Tags |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=1790542 | Issue Tracking Permissions Required Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2023-13/ | Vendor Advisory |