netfilter: synproxy: fix unaligned memory access in timestamp adjustment
CVE-2026-80637 · published 28 Aug 2026
How serious is it
- Severity: high, CVSS score 7.5 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-2026-80637?
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: 48b1de4c110a7afa4b85862f6c75af817db26fad to < 95cda0446f51077c343fdd8264be2737eb25a6c3, 48b1de4c110a7afa4b85862f6c75af817db26fad to < 2b8e7aaa38002d8ee2f48d87b1f392eadd8e98c4, 48b1de4c110a7afa4b85862f6c75af817db26fad to < 5c9c67cf7a3d16051dfb90e98836f530964dfb8e, 48b1de4c110a7afa4b85862f6c75af817db26fad to < ea3d2caa5bfacf5db5c1cad521ca5d9144edd9a7
- Linux Linux: 3.12
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:
netfilter: synproxy: fix unaligned memory access in timestamp adjustment
Use get_unaligned_be32() and put_unaligned_be32() to safely read and
write the timestamp fields. This prevents performance degradation due to
unaligned memory access or even a crash on strict alignment
architectures.
This follows the implementation of timestamp parsing in the networking
stack at tcp_parse_options() and synproxy_parse_options().
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/95cda0446f51077c343fdd8264be2737eb25a6c3
- git.kernel.org/stable/c/2b8e7aaa38002d8ee2f48d87b1f392eadd8e98c4
- git.kernel.org/stable/c/5c9c67cf7a3d16051dfb90e98836f530964dfb8e
- git.kernel.org/stable/c/ea3d2caa5bfacf5db5c1cad521ca5d9144edd9a7
- git.kernel.org/stable/c/992c20bc8a4aba220c8b95b467d049289778dad6
Merged from CVE List. Last updated 26 Oct 2026. All vulnerabilities · RSS · JSON