CVE-2025-1935: mozilla firefox Cross-site Scripting
CVSS: 4.3v3.1MediumModified
AliasesUBUNTU-CVE-2025-1935DEBIAN-CVE-2025-1935CGA-mhcr-xq52-fhgmCGA-mm39-8mpg-cmh9CGA-g2qx-h33w-4g42CGA-gcgq-8w89-3g93
Published 04-03-2025Last modified 04-06-2026
Vulnerability summary
CVE-2025-1935 is a medium (CVSS 4.3) Cross-site Scripting vulnerability in mozilla firefox. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 26.3% of scored vulnerabilities.
CVSS score
4.3/10
010
Medium · v3.1 (CVE.org)EPSS score
0.34%
0%100%
Low · +0.01 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 25 · Related 10DLA-4078-1DLA-4081-1DSA-5874-1DSA-5876-1MGASA-2025-0092MGASA-2025-0093OPENSUSE-SU-2025:14852-1OPENSUSE-SU-2025:14853-1OPENSUSE-SU-2025:14861-1OPENSUSE-SU-2025:14958-1RHSA-2025:2359RHSA-2025:2452RHSA-2025:2479RHSA-2025:2480RHSA-2025:2481RHSA-2025:2484RHSA-2025:2485RHSA-2025:2486RHSA-2025:2699RHSA-2025:2708SUSE-SU-2025:0783-1SUSE-SU-2025:0788-1SUSE-SU-2025:0849-1USN-7334-1USN-7663-1CGA-JPJ4-HX85-QPFC
Timeline
- 04-03-2025PublishedVulnerability first disclosed.
- 04-06-2026Last modifiedVulnerability information updated.
Description
A web page could trick a user into setting that site as the default handler for a custom URL protocol. This vulnerability was fixed in Firefox 136, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.
CVSS metrics
6 scores · 6 sources · 1 versionMedium 4.3Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:NSourcesAll 6 agree
- OSV · UbuntuEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
- OSV · DebianEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
- OSV · WolfiEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
- OSV · ChainguardEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
- NVDNIST4.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.34%
Chance of exploitation in the next 30 days
Percentile
26%
Versus all other CVEs
30-day change
+0.01 pp
From 0.34% on 20-09-2026
20-09-202620-10-2026
EPSS score0.34%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu9 products
- firefox< 136.0+build3-0ubuntu0.20.04.1
- mozjs102All versions (No fix recorded)
- mozjs115All versions (No fix recorded)
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
Chainguard2 products
- firefox< 136-r0
- firefox-esr< 136-r0
Debian2 products
- firefox-esr< 128.8.0esr-1~deb12u1 | < 128.8.0esr-1
- thunderbird< 1:128.8.0esr-1~deb12u1 | < 1:128.8.0esr-1
Mozilla2 products
- firefox< 128.8.0 | < 136.0
- thunderbird< 128.8.0 | ≥ 129.0, < 136.0
Wolfi1 product
- firefox< 136-r0
5 vendors · 16 products
