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7.8

CVE-2026-46300: Linux Kernel: Coalescing Fragments Can Cause Data Corruption

CVE-2026-46300
Summary

This issue affects the Linux kernel's networking component. If not fixed, it could allow unauthorized access to encrypted data. To address this, update your Linux kernel to the latest version.

What to do

No fix is available yet. Check with your software vendor for updates.

Affected software
VendorProductAffected versions
linux linux_kernel >= 3.9, <= 5.10.257
>= 5.11, < 5.15.208
>= 5.16, < 6.1.174
>= 6.2, < 6.6.141
>= 6.7, < 6.12.91
>= 6.13, < 6.18.33
>= 6.19, < 7.0.10
7.1
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Original title
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 @fr...
Original description
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.
nvd CVSS3.1 7.8
Vulnerability type
CWE-787 Out-of-bounds Write
Published: 23 May 2026 · Updated: 31 May 2026 · First seen: 26 May 2026