Description
Under certain circumstances the "fetch()" API can return transient local copies of resources that were sent with a "no-store" or "no-cache" cache header instead of downloading a copy from the network as it should. This can result in previously stored, locally cached data of a website being accessible to users if they share a common profile while browsing. This vulnerability affects Firefox ESR < 52.7 and Firefox < 59.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox ESR | unspecified – < 52.7 | 52.7 |
| Mozilla | Firefox | unspecified – < 59 | 59 |
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 13 | firefox-esr | 52.7.0esr-1 | — |
| Debian 12 | firefox-esr | 52.7.0esr-1 | — |
| Debian 9 | firefox-esr | 52.7.1esr-1~deb9u1 | DSA-4139-1 |
| Debian 8 | firefox-esr | 52.7.1esr-1~deb8u1 | DSA-4139-1 |
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 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | firefox | 59.0.1+build1-0ubuntu1 | — |
| Ubuntu 16.04 LTS | firefox | 59.0+build5-0ubuntu0.16.04.1 | USN-3596-1 |
| Ubuntu 14.04 LTS | firefox | 59.0+build5-0ubuntu0.14.04.1 | USN-3596-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | firefox | 52.7.0-1.el7_4 | RHSA-2018:0527 |
| RHEL 6 | firefox | 52.7.0-1.el6_9 | 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 4 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 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 | MozillaFirefox | 92.0-1.2 | openSUSE-SU-2024:10600-1 |
| 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 | 52.7.0-1.0.1.el7_4 | ELSA-2018-0527 |
Advisories 10
- 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-3596-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4139-1 firefox-esr - 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-2024:10600-1 MozillaFirefox-92.0-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0907-1 Security update for MozillaFirefox 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-2024:14572-1 firefox-esr-128.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2018-0527 Critical: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 15, 2018
References
- DSA-4139 vendor-advisory
- GLSA-201810-01 vendor-advisory
- 103388 vdb-entry
- RHSA-2018:0527 vendor-advisory
- [debian-lts-announce] 20180315 [SECURITY] [DLA 1308-1] firefox-esr security update mailing-list
- https://www.mozilla.org/security/advisories/mfsa2018-07/
- RHSA-2018:0526 vendor-advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1440775
- 1040514 vdb-entry
- USN-3596-1 vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2018-06/