CVE-2026-29008

Name
CVE-2026-29008
Description
U-Boot through 2026.04-rc3 contains an integer underflow vulnerability in the tcp_rx_state_machine() function (net/tcp.c) that allows a network-adjacent attacker to crash the bootloader by sending a malformed TCP SYN+ACK packet with a manipulated data offset field causing payload_len to become negative. When the TCP_SYN_SENT handler calls tcp_rx_user_data() without invoking tcp_seg_in_wnd() validation, the negative payload_len is implicitly converted to a large unsigned integer (e.g., 0xFFFFFFD8) and passed to memcpy() in store_block(), causing an immediate crash that prevents device boot and may enable memory corruption when CONFIG_LMB is disabled.
NVD Severity
unknown
Other trackers
CVE, NVD, CERT, CVE Details, CIRCL, Arch Linux, Debian, Red Hat, Ubuntu, Gentoo, SUSE (Bugzilla), SUSE (CVE), Mageia
Mailing lists
oss-security, full-disclosure, bugtraq
Exploits
Exploit DB, Metasploit
Forges
GitHub (code, issues), Aports (code, issues)

References

Type URI
disclosure@vulncheck.com https://lists.denx.de/pipermail/u-boot/2026-May/617853.html
disclosure@vulncheck.com https://u-boot.org/
disclosure@vulncheck.com https://www.vulncheck.com/advisories/u-boot-rc3-integer-underflow-dos-via-tcp-rx-state-machine
disclosure@vulncheck.com https://y637f9qq2x.com/posts/u-boot-tcp-nfs-vulns/

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:denx:u-boot:*:*:*:*:*:*:*:* u-boot >= None < 2026.04

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
u-boot edge-main 2026.01-r1 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2026.01-r0 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.10-r6 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.10-r5 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.10-r4 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.10-r3 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.10-r2 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.10-r1 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.10-r0 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.07-r5 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.07-r4 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.07-r3 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.07-r2 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.07-r1 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.07-r0 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.04-r2 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.04-r1 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.04-r0 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2025.01-r0 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2024.10-r3 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2024.10-r2 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2021.04-r4 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2021.04-r3 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2021.04-r2 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot edge-main 2021.04-r0 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.23-main 2025.10-r5 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.23-main 2025.10-r4 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.22-main 2025.04-r7 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.22-main 2025.04-r6 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.22-main 2025.04-r5 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.22-main 2025.04-r4 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.22-main 2025.04-r3 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.22-main 2025.04-r2 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.22-main 2025.04-r1 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.22-main 2021.04-r0 None possibly vulnerable
u-boot 3.21-main 2024.10-r8 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.21-main 2024.10-r7 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.21-main 2024.10-r6 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.21-main 2024.10-r5 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.21-main 2024.10-r4 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.21-main 2024.10-r3 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.21-main 2024.10-r2 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.21-main 2021.04-r0 None possibly vulnerable
u-boot 3.20-main 2024.04-r7 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.20-main 2024.04-r6 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.20-main 2024.04-r5 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.20-main 2024.04-r4 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.20-main 2024.04-r3 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.20-main 2024.04-r2 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.20-main 2024.04-r1 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.20-main 2021.04-r0 None possibly vulnerable
u-boot 3.19-main 2023.10-r9 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.19-main 2023.10-r8 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.19-main 2023.10-r7 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.19-main 2023.10-r6 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.19-main 2023.10-r5 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.19-main 2023.10-r4 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.19-main 2023.10-r3 Milan P. Stanić <mps@arvanta.net> possibly vulnerable
u-boot 3.19-main 2021.04-r0 None possibly vulnerable