CVE-2026-116738: kisli vmime (High, CVSS 8.7)

Remote Attacker
CVE-2026-116738Highkisli vmime
CVSS
8.7 High (v4.0)
EPSS
0.7% chance of exploitation in the next 30 days (higher than 53.8% of CVEs)
Exploited in the wild
Not on CISA’s KEV list
Public exploit
None reported in public exploit databases
Weakness
CWE-121
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Published
Oct 26, 2026

What it is

VMime through 0.9.2 contains an integer underflow in the uuEncoder::decode function that allows remote attackers to trigger a stack-based buffer overflow via crafted uuencoded MIME parts. Attackers can send an email with a uuencoded line whose length character is 'b' but is not a 'begin' line, corrupting stack memory to crash the application or potentially execute code.

Description from the National Vulnerability Database.

What to do

Check whether you run kisli vmime, then apply the vendor’s fix or mitigation from the advisories below.

Sources: NVD, FIRST EPSS, CISA KEV, and public exploit databases (availability only). ThreatRoundup reports whether public exploit code exists but never links to it: fake proof-of-concepts that infect security researchers are common. This page updates automatically.