Out-of-bounds Read in Denx U-Boot

CVE-2026-29007

U-Boot through 2026.04-rc3 contains an out-of-bounds read vulnerability in tcp_rx_state_machine() (net/tcp.c) when CONFIG_PROT_TCP is enabled, allowing remote attackers to read beyond TCP segment boundaries by crafting a malicious packet with a mismatched IP total length and TCP data offset field. Attackers can send a packet with an IP total length of 40 bytes and a TCP data offset claiming 60 bytes of header to cause tcp_parse_options() to read 40 bytes past the end of the TCP segment, potentially corrupting connection state variables such as rmt_win_scale and rmt_timestamp to disrupt TCP window calculations.

Vulnerability class: Buffer Overflow

EPSS: 0.005 (43.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-29007?
CVE-2026-29007 is a medium-severity vulnerability in Denx U-Boot, classified under Out-of-bounds Read. CVSS score: 5.3/10. Published 2026-07-08.
How severe is CVE-2026-29007?
Medium severity. CVSS v3 base score is 5.3 out of 10.