high 7.3

CVE-2025-3029 json

URL Bar Spoofing via non-BMP Unicode characters

published 2025-04-01 19 mo ago modified 2026-10-05 34 d ago also EUVD-2025-9300

cvss: 7.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 29%
public exploits: 0; none known

A crafted URL containing specific Unicode characters could have hidden the true origin of the page, resulting in a potential spoofing attack. This vulnerability was fixed in Firefox 137, Firefox ESR 128.9, Thunderbird 137, and Thunderbird 128.9.

Patch / fix

fixed in 4 distros 7

mozilla firefox 128.9, 137
mozilla firefox_esr 128.9, 137
mozilla thunderbird 128.9, 137
mozilla thunderbird_esr 128.9, 137

debian ubuntu red hat suse opensuse almalinux rocky linux

firefox-esr Debian 12 128.9.0esr-1~deb12u1
firefox-esr Debian 14, Debian 13 128.9.0esr-1
thunderbird Debian 12 1:128.9.0esr-1~deb12u1
thunderbird Debian 14, Debian 13 1:128.9.0esr-1

debian advisories DEBIAN-CVE-2025-3029

thunderbird Ubuntu 22.04 LTS 1:128.12.0+build1-0ubuntu0.22.04.1

ubuntu advisories UBUNTU-CVE-2025-3029

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

firefox RHEL 10.0 128.9.0-3.el10_0
thunderbird RHEL 10.0 128.9.0-2.el10_0
thunderbird RHEL 9 128.9.0-2.el9_5
thunderbird RHEL 8 128.9.0-2.el8_10
firefox RHEL 8 128.9.0-2.el8_10
firefox RHEL 9 128.9.0-2.el9_5
firefox-x11 RHEL 9 128.9.0-2.el9_5
thunderbird RHEL 8.2 AUS 128.9.0-2.el8_2

red hat advisories RHSA-2025:7491 RHSA-2025:7493 RHSA-2025:4169 RHSA-2025:4170 RHSA-2025:4032 RHSA-2025:4031

MozillaThunderbird SLE Workstation Extension 15 SP6, SLE Module for Package Hub 15 SP6, openSUSE Leap 15.6 128.9.0-150200.8.206.1
MozillaFirefox SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES for SAP 15 SP3 +11 more 128.9.0-150200.152.176.1
MozillaFirefox SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 128.9.0-112.252.1

suse advisories SUSE-SU-2025:1157-1 SUSE-SU-2025:1138-1 SUSE-SU-2025:1103-1

MozillaFirefox openSUSE Tumbleweed 137.0-1.1
MozillaThunderbird openSUSE Tumbleweed 128.9.0-1.1
firefox-esr openSUSE Tumbleweed 128.9.0-1.1

opensuse advisories openSUSE-SU-2025:14971-1 openSUSE-SU-2025:14966-1 openSUSE-SU-2025:14961-1

thunderbird AlmaLinux 9 128.9.0-2.el9_5.alma.1
thunderbird AlmaLinux 8 128.9.0-2.el8_10.alma.1
firefox AlmaLinux 9 128.9.0-2.el9_5
firefox-x11 AlmaLinux 9 128.9.0-2.el9_5
firefox AlmaLinux 8 128.9.0-2.el8_10

almalinux advisories ALSA-2025:4169 ALSA-2025:4170 ALSA-2025:3556 ALSA-2025:3582

firefox Rocky Linux 8 128.9.0-2.el8_10
thunderbird Rocky Linux 8 128.9.0-2.el8_10

rocky linux advisories RLSA-2025:3582 RLSA-2025:4170

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-3029 updated 2026-11-07 cvss 5.4

firefox: thunderbird: URL Bar Spoofing via non-BMP Unicode characters

Red Hat Enterprise Linux 6 firefox, thunderbird Red Hat Enterprise Linux 7 thunderbird
affected: no fix planned “Out of support scope”
Red Hat Enterprise Linux 9 firefox-flatpak-container, thunderbird-flatpak-container Red Hat Enterprise Linux 10 firefox-flatpak-container, thunderbird-flatpak-container
affected: no fix available
Red Hat Enterprise Linux AppStream (v. 8) firefox 128.9.0-2.el8_10, thunderbird 128.9.0-2.el8_10
fixed: vendor fix RHSA-2025:3582
Red Hat Enterprise Linux AppStream (v. 9) firefox 128.9.0-2.el9_5, firefox-x11 128.9.0-2.el9_5, thunderbird 128.9.0-2.el9_5
fixed: vendor fix RHSA-2025:3556
Red Hat Enterprise Linux AppStream (v. 10) firefox 128.9.0-3.el10_0, thunderbird 128.9.0-2.el10_0
fixed: vendor fix RHSA-2025:7491
Red Hat Enterprise Linux AppStream AUS (v. 8.2) firefox 128.9.0-2.el8_2, thunderbird 128.9.0-2.el8_2
fixed: vendor fix RHSA-2025:3623
Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox 128.9.0-2.el8_4, thunderbird 128.9.0-2.el8_4
fixed: vendor fix RHSA-2025:3581
Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox 128.9.0-2.el8_6, thunderbird 128.9.0-2.el8_6
fixed: vendor fix RHSA-2025:3621

show 9 more

Red Hat Enterprise Linux AppStream E4S (v.8.4) firefox 128.9.0-2.el8_4, thunderbird 128.9.0-2.el8_4
fixed: vendor fix RHSA-2025:3581
Red Hat Enterprise Linux AppStream E4S (v.8.6) firefox 128.9.0-2.el8_6, thunderbird 128.9.0-2.el8_6
fixed: vendor fix RHSA-2025:3621
Red Hat Enterprise Linux AppStream E4S (v.9.0) firefox 128.9.0-2.el9_0, thunderbird 128.9.0-2.el9_0
fixed: vendor fix RHSA-2025:3587
Red Hat Enterprise Linux AppStream EUS (v.8.8) firefox 128.9.0-2.el8_8, thunderbird 128.9.0-2.el8_8
fixed: vendor fix RHSA-2025:3620
Red Hat Enterprise Linux AppStream EUS (v.9.2) firefox 128.9.0-2.el9_2, firefox-x11 128.9.0-2.el9_2, thunderbird 128.9.0-2.el9_2
fixed: vendor fix RHSA-2025:3589
Red Hat Enterprise Linux AppStream EUS (v.9.4) firefox 128.9.0-2.el9_4, firefox-x11 128.9.0-2.el9_4, thunderbird 128.9.0-2.el9_4
fixed: vendor fix RHSA-2025:3590
Red Hat Enterprise Linux AppStream TUS (v.8.4) firefox 128.9.0-2.el8_4, thunderbird 128.9.0-2.el8_4
fixed: vendor fix RHSA-2025:3581
Red Hat Enterprise Linux AppStream TUS (v.8.6) firefox 128.9.0-2.el8_6, thunderbird 128.9.0-2.el8_6
fixed: vendor fix RHSA-2025:3621
Red Hat Enterprise Linux Server (v. 7 ELS) firefox 128.9.0-2.el7_9
fixed: vendor fix RHSA-2025:3628

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 19 mo ago (2025-04-01)

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CNA	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Affected products

Mozilla Firefox
Mozilla Thunderbird

Classification

Weakness

CWE-290 Authentication Bypass by Spoofing

References

mozilla.org /security/advisories/mfsa2025-20/
vendor-advisory
mozilla.org /security/advisories/mfsa2025-22/
vendor-advisory
mozilla.org /security/advisories/mfsa2025-23/
vendor-advisory
mozilla.org /security/advisories/mfsa2025-24/
vendor-advisory
bugzilla.mozilla.org /show_bug.cgi?id=1952213
issue-tracking, permissions-required
lists.debian.org /debian-lts-announce/2025/04/msg00005.html

Sources

CVE List CVE-2025-3029
NVD CVE-2025-3029

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary