A newline in a filename could have been used to bypass the file extension security mechanisms that replace malicious file extensions such as .lnk with .download. This could have led to accidental execution of malicious code. *This bug only affects Firefox and Thunderbird on Windows. Other versions of Firefox and Thunderbird are unaffected.* This vulnerability affects Firefox < 112, Firefox ESR < 102.10, and Thunderbird < 102.10.
Conclusion & alert: CVE-2023-29542 is rated Moderate Risk (59.7/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 0.94%). 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 | 2026-06-15 | 0.12% | 0.94% | +0.82% |
| 2 | 2025-11-21 | 2.03% | 0.12% | -1.91% |
| 3 | 2025-11-18 | — | 2.03% | — |
Full EPSS history (14 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2023-29542: 3 source package rows (firefox, firefox-esr, thunderbird); 126 state rows across 6 repos (3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 8, open 118. | https://security.alpinelinux.org/vuln/CVE-2023-29542 |
debian
|
unimportant | CVE-2023-29542 unimportant 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-2023-29542 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2023-29542 |
ubuntu
|
medium | CVE-2023-29542 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 39, ignored 17, not-affected 14. | https://ubuntu.com/security/CVE-2023-29542 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| mozilla | firefox | < 112.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* |
| mozilla | firefox_esr | < 102.10 | cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* |
| mozilla | thunderbird | < 102.10 | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=1810793 | Permissions Required |
| https://bugzilla.mozilla.org/show_bug.cgi?id=1815062 | Permissions Required |
| https://www.mozilla.org/security/advisories/mfsa2023-13/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2023-14/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2023-15/ | Vendor Advisory |