CVE-2017-7753
An out-of-bounds read occurs when applying style rules to pseudo-elements, such as ::first-line, using cached style data.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.08%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
An out-of-bounds read occurs when applying style rules to pseudo-elements, such as ::first-line, using cached style data. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.
- CVSS 3.0
- 9.1 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- EPSS
- 3.08% probability · 88th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- debian/debian linux · redhat/enterprise linux · redhat/enterprise linux desktop · redhat/enterprise linux server · redhat/enterprise linux server aus · redhat/enterprise linux server eus · redhat/enterprise linux workstation · mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
EPSS 3.1% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.securityfocus.com/bid/100315Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039124Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2017:2456Third Party Advisory
- https://access.redhat.com/errata/RHSA-2017:2534Third Party Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1353312Exploit, Issue Tracking, Patch, Vendor Advisory
- https://security.gentoo.org/glsa/201803-14Third Party Advisory
- https://www.debian.org/security/2017/dsa-3928Third Party Advisory
- https://www.debian.org/security/2017/dsa-3968Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-18/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-19/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-20/Vendor Advisory
- http://www.securityfocus.com/bid/100315Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1039124Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2017:2456Third Party Advisory
- https://access.redhat.com/errata/RHSA-2017:2534Third Party Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1353312Exploit, Issue Tracking, Patch, Vendor Advisory
- https://security.gentoo.org/glsa/201803-14Third Party Advisory
- https://www.debian.org/security/2017/dsa-3928Third Party Advisory
- https://www.debian.org/security/2017/dsa-3968Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-18/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-19/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-20/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.