FreeBSD PPP LcpDecodeConfig OOB Write via Undersized Endpoint Discriminator Option
CVE-2026-58096 Published on August 26, 2026
ppp(8): missing length validation in LcpDecodeConfig()
LcpDecodeConfig() did not validate the length of received endpoint discriminator options against the minimum required by RFC 1717. Undersized options would trigger an out-of-bounds write.
A malicious PPP peer can exploit CVE-2026-58095 and CVE-2026-58096 to crash ppp(8) or potentially execute arbitrary code as root.
Vulnerability Analysis
CVE-2026-58096 is exploitable with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.
Weakness Types
What is a length manipulation Vulnerability?
The software parses a formatted message or structure, but it does not handle or incorrectly handles a length field that is inconsistent with the actual length of the associated data. If an attacker can manipulate the length parameter associated with an input such that it is inconsistent with the actual length of the input, this can be leveraged to cause the target application to behave in unexpected, and possibly, malicious ways. One of the possible motives for doing so is to pass in arbitrarily large input to the application. Another possible motivation is the modification of application state by including invalid data for subsequent properties of the application. Such weaknesses commonly lead to attacks such as buffer overflows and execution of arbitrary code.
CVE-2026-58096 has been classified to as a length manipulation vulnerability or weakness.
What is a Memory Corruption Vulnerability?
The software writes data past the end, or before the beginning, of the intended buffer. Typically, this can result in corruption of data, a crash, or code execution. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent write operation then produces undefined or unexpected results.
CVE-2026-58096 has been classified to as a Memory Corruption vulnerability or weakness.
Products Associated with CVE-2026-58096
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Affected Versions
FreeBSD:- Version 15.1-RELEASE and below p3 is affected.
- Version 15.0-RELEASE and below p13 is affected.
- Version 14.4-RELEASE and below p9 is affected.