Linux Kernel Missing Initialization of a Variable Vulnerability
CVE-2026-46300 · GHSA-47jg-vqrv-5f8v · EUVD-2026-31535 · published 23 May 2026
How serious is it
- Severity: high, CVSS score 7.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Confirmed exploited in the wild (CISA KEV).
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-46300?
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: cef401de7be8c4e155c6746bfccf721a4fa5fab9 <2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c
- Linux Linux: cef401de7be8c4e155c6746bfccf721a4fa5fab9 <f84eca5817390257cef78013d0112481c503b4a3
- Linux Linux: patch: 6.18.33
- Linux Linux: cef401de7be8c4e155c6746bfccf721a4fa5fab9 <760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34e
- Linux Linux: cef401de7be8c4e155c6746bfccf721a4fa5fab9 <78bf6b6bb19541d19fbda6242e7cfe2c682763c0
- Linux Linux: patch: 0
- Linux Linux: patch: 7.1
- Linux Linux: patch: 6.1.174
- Linux Linux: cef401de7be8c4e155c6746bfccf721a4fa5fab9 <9d3e5fd19fe1063bf607219e8562fbd567b8e8d5
- Linux Linux: cef401de7be8c4e155c6746bfccf721a4fa5fab9 <3884358a9286b17f389a72b1426fc4547c23c111
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:
net: skbuff: preserve shared-frag marker during coalescing
skb_try_coalesce() can attach paged frags from @from to @to. If @from
has SKBFL_SHARED_FRAG set, the resulting @to skb can contain the same
externally-owned or page-cache-backed frags, but the shared-frag marker
is currently lost.
That breaks the invariant relied on by later in-place writers. In
particular, ESP input checks skb_has_shared_frag() before deciding
whether an uncloned nonlinear skb can skip skb_cow_data(). If TCP
receive coalescing has moved shared frags into an unmarked skb, ESP can
see skb_has_shared_frag() as false and decrypt in place over page-cache
backed frags.
Propagate SKBFL_SHARED_FRAG when skb_try_coalesce() transfers paged
frags. The tailroom copy path does not need the marker because it copies
bytes into @to's linear data rather than transferring frag descriptors.
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/3599e6b3cc1ada96883d496a50a210d3afbb6987
- git.kernel.org/stable/c/2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c
- git.kernel.org/stable/c/9d3e5fd19fe1063bf607219e8562fbd567b8e8d5
- git.kernel.org/stable/c/78bf6b6bb19541d19fbda6242e7cfe2c682763c0
- git.kernel.org/stable/c/760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34e
- git.kernel.org/stable/c/3bd9e113d50034db99d7ef69fd8e5242d15e414a
- git.kernel.org/stable/c/3884358a9286b17f389a72b1426fc4547c23c111
- git.kernel.org/stable/c/f84eca5817390257cef78013d0112481c503b4a3
Merged from CISA KEV, ENISA EUVD. Last updated 29 Oct 2026. All vulnerabilities · RSS · JSON