The browser engine in Mozilla Firefox 4.x through 5, SeaMonkey 2.x before 2.3, Thunderbird before 6, and possibly other products does not p…

published 2011-08-18 15 y ago modified 2026-06-16 4 mo ago also EUVD-2011-2959

cvss: 10.0; version 2.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 4.6%; EPSS 4.6% chance of exploitation in 30 days, percentile 91%
public exploits: 0; none known

The browser engine in Mozilla Firefox 4.x through 5, SeaMonkey 2.x before 2.3, Thunderbird before 6, and possibly other products does not properly implement JavaScript, which allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unspecified vectors.

Patch / fix

distros 1

MozillaFirefox openSUSE Tumbleweed 50.1.0-1.1
MozillaThunderbird openSUSE Tumbleweed 45.5.1-1.1

opensuse advisories openSUSE-SU-2024:10071-1 openSUSE-SU-2024:10230-1

Exploit prediction

4.64% chance of exploitation in the next 30 days, higher than 91% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
NVD	2.0	10.0	AV:N/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness

CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

lists.opensuse.org /opensuse-security-announce/2011-08/msg00023.html
vendor-advisory
mozilla.org /security/announce/2011/mfsa2011-29.html
vendor-advisory
mozilla.org /security/announce/2011/mfsa2011-31.html
oval.cisecurity.org /repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14303
vdb-entry, signature
mozilla.org /security/announce/2011/mfsa2011-33.html
bugzilla.mozilla.org /show_bug.cgi?id=655660
secunia.com /advisories/49055
third-party-advisory

Sources

CVE List CVE-2011-2991
NVD CVE-2011-2991

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary