Description
Memory safety bugs were reported in Firefox ESR 52.6. 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 ESR < 52.7 and Thunderbird < 52.7.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox ESR | unspecified – < 52.7 | 52.7 |
| Mozilla | Thunderbird | unspecified – < 52.7 | 52.7 |
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 | 52.7.0esr-1 | — |
| Debian 14 | thunderbird | 1:52.7.0-1 | — |
| Debian 13 | firefox-esr | 52.7.0esr-1 | — |
| Debian 13 | thunderbird | 1:52.7.0-1 | — |
| Debian 12 | firefox-esr | 52.7.0esr-1 | — |
| Debian 12 | thunderbird | 1:52.7.0-1 | — |
| Debian 9 | firefox-esr | 52.7.1esr-1~deb9u1 | DSA-4139-1 |
| Debian 9 | thunderbird | 1:52.7.0-1~deb9u1 | DSA-4155-1 |
| Debian 8 | firefox-esr | 52.7.1esr-1~deb8u1 | DSA-4139-1 |
| Debian 8 | thunderbird | 1:52.7.0-1~deb8u1 | DSA-4155-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 7 | firefox-esr | 52.7.1esr-1~deb7u1 | DLA-1308-1 |
| Debian 7 | thunderbird | 1:52.7.0-1~deb7u1 | DLA-1327-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | mozjs52 | No fix yet | — |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
| Ubuntu 18.04 LTS | thunderbird | 1:52.7.0+build1-0ubuntu1 | — |
| Ubuntu 16.04 LTS | thunderbird | 1:52.7.0+build1-0ubuntu0.16.04.1 | USN-3545-1 |
| Ubuntu 14.04 LTS | thunderbird | 1:52.7.0+build1-0ubuntu0.14.04.1 | USN-3545-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | firefox +1 | 52.7.0-1.el7_4 | RHSA-2018:0648, RHSA-2018:0527 |
| RHEL 6 | firefox +1 | 52.7.0-1.el6_9 | RHSA-2018:0647, RHSA-2018:0526 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | MozillaFirefox | 52.7.3esr-109.25.1 | SUSE-SU-2018:0850-1 |
| SLES 12 SP2 | MozillaFirefox | 52.7.3esr-109.25.1 | SUSE-SU-2018:0850-1 |
| SLES 11 SP4 | MozillaFirefox | 52.7.3esr-72.27.2 | SUSE-SU-2018:0907-1 |
| SLES 11 SP3 | MozillaFirefox | 52.7.3esr-72.27.2 | SUSE-SU-2018:0907-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP3 | MozillaFirefox | 52.7.3esr-109.25.1 | SUSE-SU-2018:0850-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 52.7.3esr-109.25.1 | SUSE-SU-2018:0850-1 |
| SLES for SAP 11 SP4 | MozillaFirefox | 52.7.3esr-72.27.2 | SUSE-SU-2018:0907-1 |
| SUSE Package Hub 12 | MozillaThunderbird | 52.7-57.1 | openSUSE-SU-2018:0819-1, openSUSE-SU-2018:0818-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | MozillaFirefox | 52.7.3esr-72.27.2 | SUSE-SU-2018:0907-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaThunderbird | 91.1.1-1.1 | openSUSE-SU-2024:10601-1 |
Advisories 14
- RHSA-2018:0648 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2018:0647 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2018:0526 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2018:0527 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-3545-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4155-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-4139-1 firefox-esr - security-update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1327-1 thunderbird - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1308-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2018:0819-1 Security update for Mozilla Thunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0907-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2018:0818-1 Security update for Mozilla Thunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0850-1 Security update for MozillaFirefox 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
References
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1261175%2C1348955
- DSA-4139 vendor-advisory
- GLSA-201811-13 vendor-advisory
- RHSA-2018:0527 vendor-advisory
- USN-3545-1 vendor-advisory
- [debian-lts-announce] 20180315 [SECURITY] [DLA 1308-1] firefox-esr security update mailing-list
- https://www.mozilla.org/security/advisories/mfsa2018-09/
- https://www.mozilla.org/security/advisories/mfsa2018-07/
- RHSA-2018:0526 vendor-advisory
- [debian-lts-announce] 20180329 [SECURITY] [DLA 1327-1] thunderbird security update mailing-list
- DSA-4155 vendor-advisory
- RHSA-2018:0648 vendor-advisory
- RHSA-2018:0647 vendor-advisory
- 1040514 vdb-entry
- 103384 vdb-entry