CVE-2023-29542

Name: CVE-2023-29542
Creator: NVD / NIST
Published: 2023-06-19T11:15:09.847+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.94%

Last modified Jun 17, 2026

CVE-2023-29542 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. EPSS estimates a 0.94% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.94%

56.4th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 112.0
Mozilla	Firefox Esr	< 102.10
Mozilla	Thunderbird	< 102.10

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1810793Permissions Required
https://bugzilla.mozilla.org/show_bug.cgi?id=1815062Permissions 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
https://bugzilla.mozilla.org/show_bug.cgi?id=1810793Permissions Required
https://bugzilla.mozilla.org/show_bug.cgi?id=1815062Permissions 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

Timeline

Published: Jun 19, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-29542?

How severe is CVE-2023-29542?

CVE-2023-29542 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.94% probability of exploitation in the next 30 days.

How do I fix CVE-2023-29542?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-29542?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST