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

> Remote attackers can read memory beyond TCP segment boundaries in U-Boot, potentially corrupting connection state and disrupting TCP operations.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Jul 2026
- **Updated:** 14 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-29007, GHSA-572m-4pr8-48pj, UBUNTU-CVE-2026-29007

## What is CVE-2026-29007?

CVE-2026-29007 is a medium-severity vulnerability in u-boot, published on 8 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-29007?

It affects 1 product.


Products: Denx U-Boot.

## How do I fix CVE-2026-29007?

No fix has been published for CVE-2026-29007 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-29007 being exploited?

There is no known exploitation of CVE-2026-29007 in the wild and no public exploit code.

## Other vulnerabilities in u-boot

- [CVE-2022-34835](https://insights.sbomify.com/CVE-2022-34835/): Integer overflow in n/a (critical 9.8)
- [CVE-2022-30767](https://insights.sbomify.com/CVE-2022-30767/): Memory corruption in n/a (critical 9.8)
- [CVE-2020-8432](https://insights.sbomify.com/CVE-2020-8432/): Use after free in n/a (critical 9.8)
- [CVE-2019-14192](https://insights.sbomify.com/CVE-2019-14192/): Integer overflow in n/a (critical 9.8)
- [CVE-2019-14193](https://insights.sbomify.com/CVE-2019-14193/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-29007 and fix it if it is affected.

What it is: CVE-2026-29007 is a medium-severity vulnerability in u-boot, published on 8 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-29007 in the wild and no public exploit code.

Affected product: u-boot. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-29007/ (Markdown: https://insights.sbomify.com/CVE-2026-29007/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-29007
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-29007
- OSV: https://osv.dev/vulnerability/CVE-2026-29007

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-29007/
Summaries are generated and may contain mistakes; the official description above is the record.