CVE-2026-29008: U-Boot versions through 2026.04-rc3 contain an integer underflow vulnerability in the
Source GCVE Database
Not known to be exploited · CVSS 7.5 High.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
AI-suggested
Until a patch is available, mitigating this vulnerability may require network-level protections to block malformed TCP SYN+ACK packets targeting the bootloader. Monitor vendor communications for updates on official fixes.
Description
U-Boot versions through 2026.04-rc3 contain an integer underflow vulnerability in the tcp_rx_state_machine() function. A network-adjacent attacker can send a malformed TCP SYN+ACK packet with a manipulated data offset field, causing the payload length to become negative. This negative value is converted to a large unsigned integer and passed to memcpy(), resulting in an immediate crash of the bootloader that prevents device boot. If CONFIG_LMB is disabled, this may also lead to memory corruption.
References
- nvd.nist.gov/vuln/detail/CVE-2026-29008 (opens in a new tab)
- lists.denx.de/pipermail/u-boot/2026-May/617853.html (opens in a new tab)
- u-boot.org (opens in a new tab)
- vulncheck.com/advisories/u-boot-rc3-integer-underflow-dos-via-tcp-rx-state-machine (opens in a new tab)
- y637f9qq2x.com/posts/u-boot-tcp-nfs-vulns (opens in a new tab)