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.
CVE-2026-29008
Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-08. a secondary CVSS source baseline 7.5; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- 49(Track)EG Risk 49/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation1% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 1%
- EPSS %ILE
- 50%
- KEV
- Not listed
Published
July 8, 2026
Last Modified
July 22, 2026
Advisory Details (3)
Auto-updated Jul 8, 2026U-Boot 2026.04-rc3 Integer Underflow DoS via tcp_rx_state_machine() | Advisories | VulnCheck
https://www.vulncheck.com/advisories/u-boot-rc3-integer-underflow-dos-via-tcp-rx-state-machineCoordinated Vulnerability Disclosure - U-Boot Multiple Vulnerabilities (3)
https://lists.denx.de/pipermail/u-boot/2026-May/617853.htmlVendor Advisories for CVE-2026-29008(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(4 across 4 ecosystems)
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| u-boot | 2021.01+dfsg-5 ... 2025.01-3.2 (53 versions) | — | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| u-boot | 2023.01+dfsg-2 ... 2025.01-3.2 (24 versions) | — | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| u-boot | 2025.01-3, 2025.01-3+deb13u1, 2025.01-3.1, 2025.01-3.2 | — | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| u-boot | 2025.01-3, 2025.01-3.1, 2025.01-3.2 | — | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 21× in last 7d / 114× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 184 total refreshes for this CVE.
- 2026-08-30 07:30 UTCEG score recompute
- 2026-08-30 07:30 UTCGHSA enrichment
- 2026-08-30 01:22 UTCEPSS rescore
- 2026-08-28 21:41 UTCEPSS rescore
- 2026-08-27 21:50 UTCEG score recompute
- 2026-08-27 21:50 UTCGHSA enrichment
- 2026-08-27 14:25 UTCEPSS rescore
- 2026-08-27 01:29 UTCEG score recompute
- 2026-08-27 01:29 UTCGHSA enrichment
- 2026-08-26 14:46 UTCEPSS rescore
- 2026-08-26 08:24 UTCEG score recompute
- 2026-08-26 08:24 UTCGHSA enrichment
- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-25 11:40 UTCGHSA enrichment
- 2026-08-24 23:49 UTCEG score recompute
- 2026-08-24 23:49 UTCGHSA enrichment
- 2026-08-24 14:17 UTCEPSS rescore
- 2026-08-24 12:37 UTCEG score recompute
- 2026-08-24 12:37 UTCGHSA enrichment
- 2026-08-24 00:48 UTCGHSA enrichment
- 2026-08-23 13:36 UTCGHSA enrichment
- 2026-08-23 02:23 UTCEG score recompute
- 2026-08-23 02:23 UTCGHSA enrichment
- 2026-08-23 00:19 UTCEPSS rescore
- 2026-08-22 15:02 UTCGHSA enrichment
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- 2026-08-22 03:47 UTCEG score recompute
- 2026-08-22 03:47 UTCGHSA enrichment
- 2026-08-21 23:49 UTCEPSS rescore
- 2026-08-21 15:11 UTCGHSA enrichment
- 2026-08-21 03:59 UTCEG score recompute
- 2026-08-21 03:59 UTCGHSA enrichment
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-20 15:37 UTCGHSA enrichment
- 2026-08-20 01:59 UTCEG score recompute
- 2026-08-20 01:59 UTCGHSA enrichment
- 2026-08-19 17:03 UTCEPSS rescore
- 2026-08-19 09:48 UTCGHSA enrichment
- 2026-08-18 22:28 UTCEG score recompute
- 2026-08-18 22:28 UTCGHSA enrichment
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-18 10:50 UTCGHSA enrichment
- 2026-08-17 22:29 UTCEG score recompute
- 2026-08-17 22:29 UTCGHSA enrichment
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-17 08:21 UTCGHSA enrichment
- 2026-08-16 21:09 UTCEG score recompute
- 2026-08-16 21:09 UTCGHSA enrichment
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 09:57 UTCEG score recompute
- 2026-08-16 09:57 UTCGHSA enrichment
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-15 22:45 UTCGHSA enrichment
- 2026-08-15 11:32 UTCEG score recompute
- 2026-08-15 11:32 UTCGHSA enrichment
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-15 00:19 UTCGHSA enrichment
- 2026-08-14 13:07 UTCGHSA enrichment
- 2026-08-14 01:54 UTCEG score recompute
- 2026-08-14 01:54 UTCGHSA enrichment
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-13 14:42 UTCGHSA enrichment
- 2026-08-13 03:29 UTCGHSA enrichment
- 2026-08-12 16:17 UTCEG score recompute
- 2026-08-12 16:17 UTCGHSA enrichment
- 2026-08-12 13:50 UTCEPSS rescore
- 2026-08-12 05:04 UTCGHSA enrichment
- 2026-08-11 17:52 UTCEG score recompute
- 2026-08-11 17:52 UTCGHSA enrichment
- 2026-08-11 13:42 UTCEPSS rescore
- 2026-08-11 06:23 UTCEG score recompute
- 2026-08-11 06:23 UTCGHSA enrichment
- 2026-08-11 00:00 UTCEPSS rescore
- 2026-08-10 19:10 UTCGHSA enrichment
- 2026-08-10 07:57 UTCGHSA enrichment
- 2026-08-09 20:45 UTCEG score recompute
- 2026-08-09 20:45 UTCGHSA enrichment
- 2026-08-09 13:46 UTCEPSS rescore
- 2026-08-09 09:33 UTCGHSA enrichment
- 2026-08-08 22:21 UTCEG score recompute
- 2026-08-08 22:21 UTCGHSA enrichment
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-08 11:08 UTCGHSA enrichment
- 2026-08-07 23:56 UTCEG score recompute
- 2026-08-07 23:56 UTCGHSA enrichment
- 2026-08-07 12:43 UTCGHSA enrichment
- 2026-08-07 01:31 UTCGHSA enrichment
- 2026-08-06 14:19 UTCEG score recompute
- 2026-08-06 14:18 UTCGHSA enrichment
- 2026-08-06 13:46 UTCEPSS rescore
- 2026-08-06 03:05 UTCEG score recompute
- 2026-08-06 03:05 UTCGHSA enrichment
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-05 15:52 UTCGHSA enrichment
- 2026-08-05 01:26 UTCEG score recompute
- 2026-08-05 01:26 UTCGHSA enrichment
- 2026-08-04 15:10 UTCEPSS rescore
- 2026-08-04 14:04 UTCEG score recompute
- 2026-08-04 14:04 UTCGHSA enrichment
- 2026-08-04 02:50 UTCGHSA enrichment
Related CVEs(same CWE)
Same CWE
10 shownCWE-191
Frequently asked(5)
What is CVE-2026-29008?
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What is the CVSS score of CVE-2026-29008?
How do I remediate CVE-2026-29008?
Dependency Blast Radius
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