ipvs: revalidate ihl to prevent out-of-bounds access
CVE-2026-74747 · published 26 Aug 2026
How serious is it
- Severity: high, CVSS score 7.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-74747?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 2512289cbf58706fd558e8fccea4e28003a2af54, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 041b2303c8019394735c1f76c5138657bf660a7d, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < eb81c8e758f49e04391f77d9470a6232bb5f1c7a, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 5365f012451fce2453f13a568dcb72ea534c1e4d
- Linux Linux: 2.6.12
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
ipvs: revalidate ihl to prevent out-of-bounds access
While the outer IP header is already pulled into the skb head,
we must be careful and revalidate the embedded headers after
reading them from the skb frags to prevent out-of-bounds
access.
One such place reported by Sashiko is ip_vs_nat_icmp() where
local process can change the ihl field and after
skb_ensure_writable() we can see larger value which is a
problem for the ip_send_check(cih) calls.
Add check to drop the packet if the ihl field is changed.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/2512289cbf58706fd558e8fccea4e28003a2af54
- git.kernel.org/stable/c/041b2303c8019394735c1f76c5138657bf660a7d
- git.kernel.org/stable/c/eb81c8e758f49e04391f77d9470a6232bb5f1c7a
- git.kernel.org/stable/c/5365f012451fce2453f13a568dcb72ea534c1e4d
- git.kernel.org/stable/c/d93660df4dd1d116f608ada4a29a80a5d6f0a6ed
Merged from CVE List. Last updated 25 Oct 2026. All vulnerabilities · RSS · JSON