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…
Does this matter?
Lower severity and a low EPSS score (0.67%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.67% probability · 50th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- denx/u-boot
- Source
- disclosure@vulncheck.com
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.