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Vulnerability · Published Jul 8, 2026 · Assigned by VulnCheck

CVE-2026-29007U-Boot 2026.04-rc3 Out-of-Bounds Read in tcp_rx_state_machine via tcp.c

Medium 5.3

In plain English

A medium-severity out-of-bounds read in u-boot from u-boot. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.7%top 47.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12u-bootno fix listedDEBIAN-CVE-2026-29007
Debian:13u-bootno fix listedDEBIAN-CVE-2026-29007
Debian:14u-bootno fix listedDEBIAN-CVE-2026-29007
Ubuntu:22.04:LTSu-bootno fix listedUBUNTU-CVE-2026-29007
Ubuntu:24.04:LTSu-bootno fix listedUBUNTU-CVE-2026-29007
Ubuntu:25.10u-bootno fix listedUBUNTU-CVE-2026-29007
Ubuntu:26.04:LTSu-bootno fix listedUBUNTU-CVE-2026-29007
Ubuntu:26.10u-bootno fix listedUBUNTU-CVE-2026-29007
Ubuntu:22.04:LTSu-boot-nezhano fix listedUBUNTU-CVE-2026-29007
Ubuntu:24.04:LTSu-boot-nezhano fix listedUBUNTU-CVE-2026-29007

Affected products (as reported)

VendorProductVersions
u-boot u-boot 0 – through 2026.04-rc3

Weakness: CWE-125 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References