Description
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| u-boot | u-boot | <= 2026.04-rc3 |
References
- https://lists.denx.de/pipermail/u-boot/2026-May/617853.htmlMailing List, Third Party Advisory
- https://u-boot.org/Product
- https://www.vulncheck.com/advisories/u-boot-rc3-out-of-bounds-read-in-tcp-rx-state-machine-via-tcp-cThird Party Advisory, Exploit
- https://y637f9qq2x.com/posts/u-boot-tcp-nfs-vulns/Third Party Advisory, Exploit
Timeline
- Published
- Jul 8, 2026
- Last modified
- Jul 22, 2026
- NVD status
- Analyzed