high 7.5

CVE-2025-1937 json

Memory safety bugs fixed in Firefox 136, Thunderbird 136, Firefox ESR 115.21, Firefox ESR 128.8, and Thunderbird 128.8

published 2025-03-04 20 mo ago modified 2026-10-05 34 d ago also EUVD-2025-6082

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 46%
public exploits: 0; none known

Memory safety bugs present in Firefox 135, Thunderbird 135, Firefox ESR 115.20, Firefox ESR 128.7, and Thunderbird 128.7. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 136, Firefox ESR 115.21, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.

Patch / fix

fixed in 3 distros 7

mozilla firefox 115.21, 128.8, 136
mozilla firefox_esr 115.21, 128.8, 136
mozilla thunderbird 128.8, 136

debian ubuntu red hat suse opensuse almalinux rocky linux

firefox-esr Debian 12 128.8.0esr-1~deb12u1
firefox-esr Debian 14, Debian 13 128.8.0esr-1
thunderbird Debian 12 1:128.8.0esr-1~deb12u1
thunderbird Debian 14, Debian 13 1:128.8.0esr-1

debian advisories DEBIAN-CVE-2025-1937

firefox Ubuntu 20.04 LTS 136.0+build3-0ubuntu0.20.04.1
thunderbird Ubuntu 22.04 LTS 1:128.12.0+build1-0ubuntu0.22.04.1

ubuntu advisories UBUNTU-CVE-2025-1937

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

thunderbird RHEL 9 128.8.0-2.el9_5
thunderbird RHEL 8 128.8.0-2.el8_10
firefox RHEL 8 128.8.0-1.el8_10
firefox RHEL 9 128.8.0-1.el9_5
firefox-x11 RHEL 9 128.8.0-1.el9_5
thunderbird RHEL 8.6 TUS, RHEL 8.6 E4S, RHEL 8.6 AUS 128.8.0-2.el8_6
thunderbird RHEL 8.4 TUS, RHEL 8.4 E4S, RHEL 8.4 AUS 128.8.0-2.el8_4
thunderbird RHEL 9.0 E4S 128.8.0-2.el9_0

red hat advisories RHSA-2025:3036 RHSA-2025:3009 RHSA-2025:3013 RHSA-2025:2960 RHSA-2025:2958 RHSA-2025:2959

MozillaThunderbird SLE Workstation Extension 15 SP6, SLE Module for Package Hub 15 SP6, openSUSE Leap 15.6 128.8.0-150200.8.203.1
MozillaFirefox SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES for SAP 15 SP3 +11 more 128.8.0-150200.152.173.1
MozillaFirefox SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 128.8.0-112.249.3

suse advisories SUSE-SU-2025:0849-1 SUSE-SU-2025:0788-1 SUSE-SU-2025:0783-1

MozillaFirefox openSUSE Tumbleweed 136.0-1.1
MozillaThunderbird openSUSE Tumbleweed 128.8.0-1.1
firefox-esr openSUSE Tumbleweed 128.8.0-1.1

opensuse advisories openSUSE-SU-2025:14861-1 openSUSE-SU-2025:14853-1 openSUSE-SU-2025:14852-1

thunderbird AlmaLinux 9 128.8.0-2.el9_5.alma.1
thunderbird AlmaLinux 8 128.8.0-2.el8_10.alma.1
firefox AlmaLinux 8 128.8.0-1.el8_10
firefox AlmaLinux 9 128.8.0-1.el9_5
firefox-x11 AlmaLinux 9 128.8.0-1.el9_5

almalinux advisories ALSA-2025:2899 ALSA-2025:2900 ALSA-2025:2452 ALSA-2025:2359

firefox Rocky Linux 8 128.8.0-1.el8_10
thunderbird Rocky Linux 8 128.8.0-2.el8_10

rocky linux advisories RLSA-2025:2452 RLSA-2025:2900

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-2025-1937 updated 2026-11-04 cvss 8.8

firefox: thunderbird: Memory safety bugs fixed in Firefox 136, Thunderbird 136, Firefox ESR 115.21, Firefox ESR 128.8, and Thunderbird 128.8

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
affected: no fix available
Red Hat Enterprise Linux AppStream (v. 8) firefox 128.8.0-1.el8_10, thunderbird 128.8.0-2.el8_10
fixed: vendor fix RHSA-2025:2452
Red Hat Enterprise Linux AppStream (v. 9) firefox 128.8.0-1.el9_5, firefox-x11 128.8.0-1.el9_5, thunderbird 128.8.0-2.el9_5
fixed: vendor fix RHSA-2025:2359
Red Hat Enterprise Linux AppStream AUS (v. 8.2) firefox 128.8.0-1.el8_2, thunderbird 128.8.0-2.el8_2
fixed: vendor fix RHSA-2025:2708
Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox 128.8.0-1.el8_4, thunderbird 128.8.0-2.el8_4
fixed: vendor fix RHSA-2025:2484
Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox 128.8.0-1.el8_6, thunderbird 128.8.0-2.el8_6
fixed: vendor fix RHSA-2025:2485
Red Hat Enterprise Linux AppStream E4S (v.8.4) firefox 128.8.0-1.el8_4, thunderbird 128.8.0-2.el8_4
fixed: vendor fix RHSA-2025:2484

show 9 more

Red Hat Enterprise Linux AppStream E4S (v.8.6) firefox 128.8.0-1.el8_6, thunderbird 128.8.0-2.el8_6
fixed: vendor fix RHSA-2025:2485
Red Hat Enterprise Linux AppStream E4S (v.9.0) firefox 128.8.0-1.el9_0, thunderbird 128.8.0-2.el9_0
fixed: vendor fix RHSA-2025:2481
Red Hat Enterprise Linux AppStream EUS (v.8.8) firefox 128.8.0-1.el8_8, thunderbird 128.8.0-2.el8_8
fixed: vendor fix RHSA-2025:2486
Red Hat Enterprise Linux AppStream EUS (v.9.2) firefox 128.8.0-1.el9_2, firefox-x11 128.8.0-1.el9_2, thunderbird 128.8.0-2.el9_2
fixed: vendor fix RHSA-2025:2480
Red Hat Enterprise Linux AppStream EUS (v.9.4) firefox 128.8.0-1.el9_4, firefox-x11 128.8.0-1.el9_4, thunderbird 128.8.0-2.el9_4
fixed: vendor fix RHSA-2025:2479
Red Hat Enterprise Linux AppStream TUS (v.8.4) firefox 128.8.0-1.el8_4, thunderbird 128.8.0-2.el8_4
fixed: vendor fix RHSA-2025:2484
Red Hat Enterprise Linux AppStream TUS (v.8.6) firefox 128.8.0-1.el8_6, thunderbird 128.8.0-2.el8_6
fixed: vendor fix RHSA-2025:2485
Red Hat Enterprise Linux Server (v. 7 ELS) firefox 128.8.0-1.el7_9
fixed: vendor fix RHSA-2025:2699
Red Hat Enterprise Linux 10 thunderbird, firefox-flatpak-container, thunderbird-flatpak-container
not affected: vulnerable code not present

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: total
Assessed: 20 mo ago (2025-03-06)

Exploit prediction

0.56% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

bugzilla.mozilla.org https://bugzilla.mozilla.org/buglist.cgi?bug_id=1938471%2C1940716 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	7.5	CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

Mozilla Firefox
Mozilla Thunderbird

Classification

Weakness

CWE-1260 Improper Handling of Overlap Between Protected Memory Ranges

References

bugzilla.mozilla.org /buglist.cgi?bug_id=1938471%2C1940716
exploit
mozilla.org /security/advisories/mfsa2025-14/
vendor-advisory
mozilla.org /security/advisories/mfsa2025-15/
vendor-advisory
mozilla.org /security/advisories/mfsa2025-16/
vendor-advisory
mozilla.org /security/advisories/mfsa2025-17/
vendor-advisory
mozilla.org /security/advisories/mfsa2025-18/
vendor-advisory
openwall.com /lists/oss-security/2025/03/10/6
vendor-advisory
lists.debian.org /debian-lts-announce/2025/03/msg00006.html

Sources

CVE List CVE-2025-1937
NVD CVE-2025-1937

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