| Name | CVE-2020-26951 |
| Description | A parsing and event loading mismatch in Firefox's SVG code could have allowed load events to fire, even after sanitization. An attacker already capable of exploiting an XSS vulnerability in privileged internal pages could have used this attack to bypass our built-in sanitizer. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-2457-1, DLA-2464-1, DSA-4793-1, DSA-4796-1 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| firefox (PTS) | sid | 133.0.3-1 | fixed |
| firefox-esr (PTS) | jessie, jessie (lts) | 68.9.0esr-1~deb8u2 | vulnerable |
| stretch (security), stretch (lts), stretch | 91.11.0esr-1~deb9u1 | fixed | |
| buster (security), buster, buster (lts) | 115.12.0esr-1~deb10u1 | fixed | |
| bullseye | 115.14.0esr-1~deb11u1 | fixed | |
| bullseye (security) | 128.5.0esr-1~deb11u1 | fixed | |
| bookworm | 128.3.1esr-1~deb12u1 | fixed | |
| bookworm (security) | 128.5.0esr-1~deb12u1 | fixed | |
| trixie | 128.5.0esr-1 | fixed | |
| sid | 128.5.1esr-1 | fixed | |
| thunderbird (PTS) | jessie, jessie (lts) | 1:68.9.0-1~deb8u2 | vulnerable |
| stretch (security), stretch (lts), stretch | 1:91.10.0-1~deb9u1 | fixed | |
| buster (security), buster, buster (lts) | 1:115.12.0-1~deb10u1 | fixed | |
| bullseye | 1:115.12.0-1~deb11u1 | fixed | |
| bullseye (security) | 1:128.5.0esr-1~deb11u1 | fixed | |
| bookworm | 1:115.16.0esr-1~deb12u1 | fixed | |
| bookworm (security) | 1:128.5.0esr-1~deb12u1 | fixed | |
| sid, trixie | 1:128.5.2esr-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| firefox | source | (unstable) | 83.0-1 | |||
| firefox-esr | source | jessie | (unfixed) | end-of-life | ||
| firefox-esr | source | stretch | 78.5.0esr-1~deb9u1 | DLA-2457-1 | ||
| firefox-esr | source | buster | 78.5.0esr-1~deb10u1 | DSA-4793-1 | ||
| firefox-esr | source | (unstable) | 78.5.0esr-1 | |||
| thunderbird | source | jessie | (unfixed) | end-of-life | ||
| thunderbird | source | stretch | 1:78.5.0-1~deb9u1 | DLA-2464-1 | ||
| thunderbird | source | buster | 1:78.5.0-1~deb10u1 | DSA-4796-1 | ||
| thunderbird | source | (unstable) | 1:78.5.0-1 |
https://www.mozilla.org/en-US/security/advisories/mfsa2020-50/#CVE-2020-26951
https://www.mozilla.org/en-US/security/advisories/mfsa2020-51/#CVE-2020-26951
https://www.mozilla.org/en-US/security/advisories/mfsa2020-52/#CVE-2020-26951