CVE-2026-46300

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.

Affected products

Linuxmint, Linux Kernel, Red Os, Rocky Linux, Ubuntu

Linux Linux Kernel

≤ 5.10.257, 5.15.208, 6.1.174, 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1

Fix

Available

CVSS 3.1

7.8 HIGH

EPSS

7.0% (94th percentile)

Weakness

CWE-123, CWE-787

NVD status

Modified

Published

2026-05-23