medium 6.5

CVE-2020-15652 json

By observing the stack trace for JavaScript errors in web workers, it was possible to leak the result of a cross-origin redirect.

published 2020-08-10 6y ago modified 2026-06-17 4mo ago also EUVD-2020-7639

cvss: 6.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.3%; EPSS 1.3% chance of exploitation in 30 days, percentile 69%
public exploits: 0; none known

By observing the stack trace for JavaScript errors in web workers, it was possible to leak the result of a cross-origin redirect. This applied only to content that can be parsed as script. This vulnerability affects Firefox < 79, Firefox ESR < 68.11, Firefox ESR < 78.1, Thunderbird < 68.11, and Thunderbird < 78.1.

Patch / fix

fixed in 3 distros 7

Mozilla Firefox 79
Mozilla Firefox ESR 68.11, 78.1
Mozilla Thunderbird 68.11, 78.1

debian ubuntu red hat suse opensuse alpine arch linux

firefox-esr Debian 14, Debian 13, Debian 12 68.11.0esr-1
thunderbird Debian 14, Debian 13, Debian 12 1:68.11.0-1

debian advisories DEBIAN-CVE-2020-15652

firefox Ubuntu 16.04 LTS 79.0+build1-0ubuntu0.16.04.2
firefox Ubuntu 18.04 LTS 79.0+build1-0ubuntu0.18.04.1
firefox Ubuntu 20.04 LTS 79.0+build1-0ubuntu0.20.04.1
thunderbird Ubuntu 18.04 LTS 1:78.8.1+build1-0ubuntu0.18.04.1
thunderbird Ubuntu 20.04 LTS 1:78.7.1+build1-0ubuntu0.20.04.1

ubuntu advisories UBUNTU-CVE-2020-15652

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 6 68.11.0-1.el6_10
thunderbird RHEL 7 68.11.0-1.el7_8
thunderbird RHEL 8 68.11.0-1.el8_2
firefox RHEL 7 68.11.0-1.el7_8
firefox RHEL 8 68.11.0-1.el8_2
firefox RHEL 6 68.11.0-1.el6_10
thunderbird RHEL 8.1 EUS 68.11.0-1.el8_1
thunderbird RHEL 8.0 E4S 68.11.0-1.el8_0

red hat advisories RHSA-2020:3345 RHSA-2020:3344 RHSA-2020:3341 RHSA-2020:3342 RHSA-2020:3343 RHSA-2020:3254

MozillaThunderbird SLE Workstation Extension 15 SP2, SLE Workstation Extension 15 SP1 68.11.0-3.91.1
MozillaFirefox SLE Module for Desktop Applications 15 SP2 78.1.0-8.3.1
pipewire SLE Module for Desktop Applications 15 SP2 0.3.6-3.3.2
MozillaFirefox-branding-SLE SLE Module for Desktop Applications 15 SP2 78-9.2.4
MozillaFirefox SLE Module for Desktop Applications 15 SP1 78.1.0-3.100.2
MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +15 more 78.1.0-112.8.1
MozillaFirefox SLES 11 SP4-LTSS 78.1.0-78.87.1

suse advisories SUSE-SU-2020:14456-1 SUSE-SU-2020:2179-1 SUSE-SU-2020:2147-1 SUSE-SU-2020:2118-1 SUSE-SU-2020:2100-1

firefox-esr openSUSE Tumbleweed 128.5.1-1.1
MozillaFirefox openSUSE Tumbleweed 92.0-1.2
MozillaThunderbird openSUSE Tumbleweed 91.1.1-1.1
MozillaThunderbird openSUSE Leap 15.2 68.11.0-lp152.2.7.1
MozillaFirefox openSUSE Leap 15.2 78.1.0-lp152.2.15.1
pipewire openSUSE Leap 15.2 0.3.6-lp152.2.3.1
MozillaThunderbird openSUSE Leap 15.1 68.11.0-lp151.2.47.1
MozillaFirefox openSUSE Leap 15.2 78.1.0-lp152.2.12.1

opensuse advisories openSUSE-SU-2024:14572-1 openSUSE-SU-2024:10600-1 openSUSE-SU-2024:10601-1 openSUSE-SU-2020:1205-1 openSUSE-SU-2020:1189-1 openSUSE-SU-2020:1179-1

firefox Alpine 3.23, Alpine 3.22, Alpine 3.21 +9 more 79.0-r0
mozjs68 Alpine 3.12 68.11.0-r0
librewolf Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 79.0-r0
firefox-esr Alpine 3.11 68.11.0-r0
firefox-esr Alpine 3.23, Alpine 3.22, Alpine 3.21 +9 more 78.1.0-r0

alpine advisories ALPINE-CVE-2020-15652

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

firefox Arch Linux 79.0-1
thunderbird Arch Linux 68.12.0-1

arch linux advisories AVG-1213 AVG-1214

Is CVE-2020-15652 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

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-2020-15652 updated 2026-11-07 cvss 6.5

Mozilla: Potential leak of redirect targets when loading scripts in a worker

Red Hat Enterprise Linux 5 firefox, thunderbird
affected: no fix planned “Out of support scope”
Red Hat Enterprise Linux AppStream (v. 8) firefox 68.11.0-1.el8_2, thunderbird 68.11.0-1.el8_2
fixed: vendor fix RHSA-2020:3241
Red Hat Enterprise Linux AppStream E4S (v. 8.0) firefox 68.11.0-1.el8_0, thunderbird 68.11.0-1.el8_0
fixed: vendor fix RHSA-2020:3229
Red Hat Enterprise Linux AppStream EUS (v. 8.1) firefox 68.11.0-1.el8_1, thunderbird 68.11.0-1.el8_1
fixed: vendor fix RHSA-2020:3254
Red Hat Enterprise Linux Client (v. 7) firefox 68.11.0-1.el7_8, thunderbird 68.11.0-1.el7_8 Red Hat Enterprise Linux Client Optional (v. 7) firefox 68.11.0-1.el7_8
fixed: vendor fix RHSA-2020:3253
Red Hat Enterprise Linux Desktop (v. 6) firefox 68.11.0-1.el6_10, thunderbird 68.11.0-1.el6_10 Red Hat Enterprise Linux Desktop Optional (v. 6) firefox 68.11.0-1.el6_10 Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox 68.11.0-1.el6_10 Red Hat Enterprise Linux Server (v. 6) firefox 68.11.0-1.el6_10
fixed: vendor fix RHSA-2020:3233
Red Hat Enterprise Linux Server (v. 7) firefox 68.11.0-1.el7_8
fixed: vendor fix RHSA-2020:3253
Red Hat Enterprise Linux Server Optional (v. 6) firefox 68.11.0-1.el6_10, thunderbird 68.11.0-1.el6_10
fixed: vendor fix RHSA-2020:3233

show 5 more

Red Hat Enterprise Linux Server Optional (v. 7) firefox 68.11.0-1.el7_8, thunderbird 68.11.0-1.el7_8
fixed: vendor fix RHSA-2020:3253
Red Hat Enterprise Linux Workstation (v. 6) firefox 68.11.0-1.el6_10, thunderbird 68.11.0-1.el6_10
fixed: vendor fix RHSA-2020:3233
Red Hat Enterprise Linux Workstation (v. 7) firefox 68.11.0-1.el7_8, thunderbird 68.11.0-1.el7_8
fixed: vendor fix RHSA-2020:3253
Red Hat Enterprise Linux Workstation Optional (v. 6) firefox 68.11.0-1.el6_10
fixed: vendor fix RHSA-2020:3233
Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 68.11.0-1.el7_8
fixed: vendor fix RHSA-2020:3253

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

Exploit prediction

1.26% chance of exploitation in the next 30 days, higher than 69% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:P/I:N/A:N

Affected products

Mozilla Firefox
Mozilla Firefox ESR
Mozilla Thunderbird

Classification

Weakness

CWE-346 Origin Validation Error

References

lists.opensuse.org /opensuse-security-announce/2020-08/msg00022.html
vendor-advisory, third-party-advisory
lists.opensuse.org /opensuse-security-announce/2020-08/msg00025.html
vendor-advisory, third-party-advisory
lists.opensuse.org /opensuse-security-announce/2020-08/msg00032.html
vendor-advisory, broken-link
usn.ubuntu.com /4443-1/
vendor-advisory, third-party-advisory
mozilla.org /security/advisories/mfsa2020-30/
vendor-advisory
mozilla.org /security/advisories/mfsa2020-35/
vendor-advisory
mozilla.org /security/advisories/mfsa2020-32/
vendor-advisory
mozilla.org /security/advisories/mfsa2020-33/
vendor-advisory
mozilla.org /security/advisories/mfsa2020-31/
vendor-advisory
bugzilla.mozilla.org /show_bug.cgi?id=1634872
issue-tracking, vendor-advisory

Sources

CVE List CVE-2020-15652
NVD CVE-2020-15652

Fencer Intel 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.

json all entries feed