UBUNTU-CVE-2026-116738: Buffer Overflow
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.
Affected Software
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Applications using Ubuntu's libvmime and processing attacker-controlled uuencoded MIME email parts are exposed. The issue is remotely reachable because a crafted email can trigger it when the application decodes the affected content.
What does an attacker need to send to trigger the flaw?
The attacker needs to send an email containing a crafted uuencoded MIME part. Specifically, the uuencoded line has a length character of 'b' and is not a 'begin' line; no authentication is required, but user interaction is required according to the supplied vector.
What is the potential impact of successful exploitation?
The malformed MIME content can corrupt stack memory through a stack-based buffer overflow. This can crash the affected application or potentially allow code execution, with high confidentiality, integrity, and availability impact.
How can I determine whether an application may be affected?
Identify applications that use libvmime and decode uuencoded MIME parts, then determine whether they are using VMime 0.9.2 or an earlier version. Email-processing paths that accept messages from untrusted senders are the most relevant to assess.