high 7.3

CVE-2025-1936 json

Adding %00 and a fake extension to a jar: URL changed the interpretation of the contents

published 2025-03-04 20 mo ago modified 2026-10-05 34 d ago also EUVD-2025-7441

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 39%
public exploits: 0; none known

jar: URLs retrieve local file content packaged in a ZIP archive. The null and everything after it was ignored when retrieving the content from the archive, but the fake extension after the null was used to determine the type of content. This could have been used to hide code in a web extension disguised as something else like an image. This vulnerability was fixed in Firefox 136, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.

Patch / fix

fixed in 4 distros 7

mozilla firefox 128.8, 136
mozilla firefox_esr 128.8, 136
mozilla thunderbird 128.8, 136
mozilla thunderbird_esr 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-2025-1936

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-2025-1936

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 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
firefox RHEL 8.2 AUS 128.8.0-1.el8_2
firefox RHEL 7 ELS 128.8.0-1.el7_9
firefox RHEL 8.6 TUS, RHEL 8.6 E4S, RHEL 8.6 AUS 128.8.0-1.el8_6
firefox RHEL 8.4 TUS, RHEL 8.4 E4S, RHEL 8.4 AUS 128.8.0-1.el8_4
firefox RHEL 8.8 EUS 128.8.0-1.el8_8

red hat advisories RHSA-2025:2708 RHSA-2025:2699 RHSA-2025:2485 RHSA-2025:2484 RHSA-2025:2486 RHSA-2025:2480

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

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-2025:2452 ALSA-2025:2359

firefox Rocky Linux 8 128.8.0-1.el8_10

rocky linux advisories RLSA-2025:2452

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-2025-1936 updated 2026-11-07 cvss 5.4

firefox: Adding %00 and a fake extension to a jar: URL changed the interpretation of the contents

Red Hat Enterprise Linux 6 firefox
affected: no fix planned “Out of support scope”
Red Hat Enterprise Linux 9 firefox-flatpak-container Red Hat Enterprise Linux 10 firefox, firefox-flatpak-container
affected: no fix available
Red Hat Enterprise Linux AppStream (v. 8) firefox 128.8.0-1.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
fixed: vendor fix RHSA-2025:2359
Red Hat Enterprise Linux AppStream AUS (v. 8.2) firefox 128.8.0-1.el8_2
fixed: vendor fix RHSA-2025:2708
Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox 128.8.0-1.el8_4
fixed: vendor fix RHSA-2025:2484
Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox 128.8.0-1.el8_6
fixed: vendor fix RHSA-2025:2485
Red Hat Enterprise Linux AppStream E4S (v.8.4) firefox 128.8.0-1.el8_4
fixed: vendor fix RHSA-2025:2484

show 8 more

Red Hat Enterprise Linux AppStream E4S (v.8.6) firefox 128.8.0-1.el8_6
fixed: vendor fix RHSA-2025:2485
Red Hat Enterprise Linux AppStream E4S (v.9.0) firefox 128.8.0-1.el9_0
fixed: vendor fix RHSA-2025:2481
Red Hat Enterprise Linux AppStream EUS (v.8.8) firefox 128.8.0-1.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
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
fixed: vendor fix RHSA-2025:2479
Red Hat Enterprise Linux AppStream TUS (v.8.4) firefox 128.8.0-1.el8_4
fixed: vendor fix RHSA-2025:2484
Red Hat Enterprise Linux AppStream TUS (v.8.6) firefox 128.8.0-1.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 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: yes
Technical impact: partial
Assessed: 19 mo ago (2025-03-25)

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% 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-158 Improper Neutralization of Null Byte or NUL Character

References

mozilla.org /security/advisories/mfsa2025-14/
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
bugzilla.mozilla.org /show_bug.cgi?id=1940027
permissions-required
lists.debian.org /debian-lts-announce/2025/03/msg00006.html

Sources

CVE List CVE-2025-1936
NVD CVE-2025-1936

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