Description
An existing mitigation of timing side-channel attacks is insufficient in some circumstances. This issue is addressed in Network Security Services (NSS) 3.26.1. This vulnerability affects Thunderbird < 45.5, Firefox ESR < 45.5, and Firefox < 50.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | unspecified – < 45.5 | 45.5 |
| Mozilla | Firefox ESR | unspecified – < 45.5 | 45.5 |
| Mozilla | Firefox | unspecified – < 50 | 50 |
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 | 45.5.0esr-1 | — |
| Debian 14 | nss | 2:3.26.2-1 | — |
| Debian 13 | firefox-esr | 45.5.0esr-1 | — |
| Debian 13 | nss | 2:3.26.2-1 | — |
| Debian 12 | firefox-esr | 45.5.0esr-1 | — |
| Debian 12 | nss | 2:3.26.2-1 | — |
| Debian 8 | firefox-esr | 45.5.0esr-1~deb8u1 | DSA-3716-1 |
| Debian 8 | icedove | 1:45.5.1-1~deb8u1 | DSA-3730-1 |
| Debian 7 | icedove | 1:45.5.1-1~deb7u1 | DLA-752-1 |
| Debian 7 | nss | 2:3.26-1+debu7u2 | DLA-759-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | nss | 2:3.26.2-0ubuntu0.16.04.2 | USN-3163-1 |
| Ubuntu 14.04 LTS | nss | 2:3.26.2-0ubuntu0.14.04.3 | USN-3163-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES 12 SP2 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES 12 SP1 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES 12 SP1 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES 12 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES 12 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES 11 SP4 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SLES 11 SP4 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
| SLES 11 SP3 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SLES 11 SP3 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP2 | MozillaFirefox | 45.5.1esr-63.1 | SUSE-SU-2016:3105-1 |
| SLES 11 SP2 | mozilla-nss | 3.21.3-30.1 | SUSE-SU-2016:3105-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 12 SP2 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 12 SP1 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 12 SP1 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 12 | MozillaFirefox | 45.5.0esr-88.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 12 | mozilla-nss | 3.21.3-50.1 | SUSE-SU-2016:3014-1 |
| SLES for SAP 11 SP4 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SLES for SAP 11 SP4 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
| SUSE OpenStack Cloud 5 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SUSE OpenStack Cloud 5 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
| SUSE Manager Proxy 2.1 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SUSE Manager Proxy 2.1 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
| SUSE Manager 2.1 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SUSE Manager 2.1 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | MozillaFirefox | 45.5.1esr-59.1 | SUSE-SU-2016:3080-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | mozilla-nss | 3.21.3-39.1 | SUSE-SU-2016:3080-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 50.1.0-1.1 | openSUSE-SU-2024:10071-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
Advisories 10
- USN-3163-1 nss vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-759-1 nss - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-752-1 icedove - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3716-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3730-1 icedove - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2016:3014-1 Security update for MozillaFirefox, mozilla-nss SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3080-1 Security update for MozillaFirefox, mozilla-nss SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:3105-1 Security update for MozillaFirefox, mozilla-nss 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-2024:10071-1 MozillaFirefox-50.1.0-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
References
- DSA-3730 vendor-advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1293334
- GLSA-201701-46 vendor-advisory
- 94341 vdb-entry
- 1037298 vdb-entry
- GLSA-201701-15 vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2016-93/
- https://www.mozilla.org/security/advisories/mfsa2016-89/
- https://www.mozilla.org/security/advisories/mfsa2016-90/