Description
Memory safety bugs were reported in Firefox 56 and Firefox ESR 52.4. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 57, Firefox ESR < 52.5, and Thunderbird < 52.5.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 57 | 57 |
| Mozilla | Firefox ESR | unspecified – < 52.5 | 52.5 |
| Mozilla | Thunderbird | unspecified – < 52.5 | 52.5 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | firefox-esr | 52.5.0esr-1 | — |
| Debian 14 | thunderbird | 1:52.5.0-1 | — |
| Debian 13 | firefox-esr | 52.5.0esr-1 | — |
| Debian 13 | thunderbird | 1:52.5.0-1 | — |
| Debian 12 | firefox-esr | 52.5.0esr-1 | — |
| Debian 12 | thunderbird | 1:52.5.0-1 | — |
| Debian 9 | firefox-esr | 52.5.0esr-1~deb9u1 | DSA-4035-1 |
| Debian 9 | thunderbird | 1:52.5.0-1~deb9u1 | DSA-4075-1, DSA-4061-1 |
| Debian 8 | firefox-esr | 52.5.0esr-1~deb8u1 | DSA-4035-1 |
| Debian 8 | thunderbird | 1:52.5.0-1~deb8u1 | DSA-4075-1, DSA-4061-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 7 | firefox-esr | 52.5.0esr-1~deb7u1 | DLA-1172-1 |
| Debian 7 | thunderbird | 1:52.5.0-1~deb7u1 | DLA-1199-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | mozjs52 | No fix yet | — |
| Ubuntu 18.04 LTS | firefox | 57.0.1+build2-0ubuntu1 | — |
| Ubuntu 18.04 LTS | mozjs38 | No fix yet | — |
| Ubuntu 18.04 LTS | mozjs52 | 52.8.1-0ubuntu0.18.04.1 | USN-3688-1 |
| Ubuntu 18.04 LTS | thunderbird | 1:52.6.0+build1-0ubuntu1 | — |
| Ubuntu 16.04 LTS | firefox | 57.0+build4-0ubuntu0.16.04.5 | USN-3477-1 |
| Ubuntu 16.04 LTS | thunderbird | 1:52.5.0+build1-0ubuntu0.16.04.1 | USN-3490-1 |
| Ubuntu 14.04 LTS | firefox | 57.0+build4-0ubuntu0.14.04.4 | USN-3477-1 |
| Ubuntu 14.04 LTS | thunderbird | 1:52.5.0+build1-0ubuntu0.14.04.1 | USN-3490-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | firefox +1 | 52.5.0-1.el7_4 | RHSA-2017:3372, RHSA-2017:3247 |
| RHEL 6 | firefox +1 | 52.5.0-1.el6_9 | RHSA-2017:3372, RHSA-2017:3247 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | MozillaFirefox | 52.5.0esr-109.9.1 | SUSE-SU-2017:3213-1 |
| SLES 12 SP2 | MozillaFirefox | 52.5.0esr-109.9.1 | SUSE-SU-2017:3213-1 |
| SLES 12 SP1 | MozillaFirefox | 52.5.0esr-109.9.1 | SUSE-SU-2017:3213-1 |
| SLES 12 | MozillaFirefox | 52.5.0esr-109.9.1 | SUSE-SU-2017:3213-1 |
| SLES 11 SP4 | MozillaFirefox | 52.5.0esr-72.17.1 | SUSE-SU-2017:3233-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP3 | MozillaFirefox | 52.5.0esr-72.17.1 | SUSE-SU-2017:3233-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 52.5.0esr-109.9.1 | SUSE-SU-2017:3213-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 52.5.0esr-109.9.1 | SUSE-SU-2017:3213-1 |
| SLES for SAP 12 SP1 | MozillaFirefox | 52.5.0esr-109.9.1 | SUSE-SU-2017:3213-1 |
| SLES for SAP 11 SP4 | MozillaFirefox | 52.5.0esr-72.17.1 | SUSE-SU-2017:3233-1 |
| SUSE Package Hub 12 | MozillaThunderbird | 52.5.0-48.1 | openSUSE-SU-2017:3110-1, openSUSE-SU-2017:3108-1 |
| SUSE OpenStack Cloud 6 | MozillaFirefox | 52.5.0esr-109.9.1 | SUSE-SU-2017:3213-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | MozillaFirefox | 52.5.0esr-72.17.1 | SUSE-SU-2017:3233-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 92.0-1.2 | openSUSE-SU-2024:10600-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 91.1.1-1.1 | openSUSE-SU-2024:10601-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | firefox +1 | 52.5.0-1.0.1.el7_4 | ELSA-2017-3372, ELSA-2017-3247 |
Advisories 19
- RHSA-2017:3372 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2017:3247 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-3688-1 mozjs52 vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3477-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3490-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4061-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-4075-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-4035-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1172-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1199-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2017:3108-1 Security update for Mozilla Thunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:3233-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:3213-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10600-1 MozillaFirefox-92.0-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2017:3110-1 Security update for Mozilla Thunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14572-1 firefox-esr-128.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10601-1 MozillaThunderbird-91.1.1-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- ELSA-2017-3372 Important: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Dec 4, 2017
- ELSA-2017-3247 Critical: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 17, 2017
References
- [debian-lts-announce] 20171209 [SECURITY] [DLA 1199-1] thunderbird security update mailing-list
- DSA-4035 vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2017-24/
- https://www.mozilla.org/security/advisories/mfsa2017-25/
- 101832 vdb-entry
- https://www.mozilla.org/security/advisories/mfsa2017-26/
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1394530%2C1369561%2C1411458%2C1400003%2C1395138%2C1408412%2C1393840%2C1400763%2C1339259%2C1394265%2C1407740%2C1407751%2C1408005%2C1406398%2C1387799%2C1261175%2C1400554%2C1375146%2C1397811%2C1404636%2C1401804
- 1039803 vdb-entry
- DSA-4061 vendor-advisory
- [debian-lts-announce] 20171115 [SECURITY] [DLA 1172-1] firefox-esr security update mailing-list
- RHSA-2017:3247 vendor-advisory
- DSA-4075 vendor-advisory
- USN-3688-1 vendor-advisory
- RHSA-2017:3372 vendor-advisory