CVE-2023-5725

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-10-25 · updated 2026-06-17

Description

A malicious installed WebExtension could open arbitrary URLs, which under the right circumstance could be leveraged to collect sensitive user data. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.

Affected products

Debian Linux: 10.0, 11.0
Mozilla Firefox: before 119.0 — fixed in 119.0
Mozilla Firefox ESR: before 115.4 — fixed in 115.4
Mozilla Thunderbird: before 115.4.1 — fixed in 115.4.1

How to fix

Upgrade to a fixed version: Mozilla Firefox 119.0; Mozilla Firefox ESR 115.4; Mozilla Thunderbird 115.4.1. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1845739
https://lists.debian.org/debian-lts-announce/2023/10/msg00037.html
https://lists.debian.org/debian-lts-announce/2023/10/msg00042.html
https://www.debian.org/security/2023/dsa-5535
https://www.debian.org/security/2023/dsa-5538
https://www.mozilla.org/security/advisories/mfsa2023-45/
https://www.mozilla.org/security/advisories/mfsa2023-46/
https://www.mozilla.org/security/advisories/mfsa2023-47/
https://bugzilla.mozilla.org/show_bug.cgi?id=1845739
https://lists.debian.org/debian-lts-announce/2023/10/msg00037.html
https://lists.debian.org/debian-lts-announce/2023/10/msg00042.html
https://www.debian.org/security/2023/dsa-5535

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