CVE-2026-29007
Description
A flaw was found in U-Boot. A remote attacker can exploit an out-of-bounds read vulnerability in the tcp_rx_state_machine() function when the Transmission Control Protocol (TCP) is enabled. By crafting a malicious packet with a mismatched IP total length and TCP data offset, an attacker can read beyond TCP segment boundaries. This can potentially corrupt connection state variables, leading to a disruption of TCP window calculations and a denial of service.
Statement
Red Hat ships U-Boot tools and related Python utility packages in Fedora and EPEL community repositories. The vulnerable code is in U-Boot's TCP state machine (tcp_rx_state_machine in net/tcp.c) and requires CONFIG_PROT_TCP to be enabled at compile time. This vulnerability does not affect any Red Hat product — only community packages.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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