SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2012-1947

Heap-based buffer overflow in the utf16_to_isolatin1 function in Mozilla Firefox 4.x through 12.0, Firefox ESR 10.x before 10.0.5, Thunderbird 5.0 through 12.0, Thunderbird ESR 10.x before 10.0.5, and SeaMonkey before 2.10 allows remote attackers to…

HIGH 9.3EPSS 4.58%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (4.58%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Heap-based buffer overflow in the utf16_to_isolatin1 function in Mozilla Firefox 4.x through 12.0, Firefox ESR 10.x before 10.0.5, Thunderbird 5.0 through 12.0, Thunderbird ESR 10.x before 10.0.5, and SeaMonkey before 2.10 allows remote attackers to execute arbitrary code via vectors that trigger a character-set conversion failure.

CVSS 2.0
9.3 HIGHAV:N/AC:M/Au:N/C:C/I:C/A:C
EPSS
4.58% probability · 92th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-119
Affected
mozilla/firefox · mozilla/seamonkey · mozilla/thunderbird · mozilla/thunderbird esr
Source
cve@mitre.org
EPSS trend
0%3%5%26 October 2026: 4.58%26 October 202626 October 2026

EPSS 4.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.