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.
CVE-2026-46300
CVSS base score
7.8 (v3.1)
Severity
HIGH
Attack vector
Local
Weakness
CWE-787, CWE-456, CWE-123
Last modified
October 29, 2026
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products
linux linux kernel
siemens simatic s7-1500 cpu 1518-4 pn\/dp mfp firmware
redhat openshift container platform
redhat enterprise linux
redhat enterprise linux aus
redhat enterprise linux eus
redhat enterprise linux tus
redhat enterprise linux update services for sap solutions
References
- git.kernel.org Patch
- git.kernel.org Patch
- git.kernel.org Patch
- git.kernel.org Patch
- git.kernel.org Patch
- git.kernel.org Patch
- git.kernel.org Patch
- git.kernel.org Patch
- www.openwall.com Mailing List
- www.openwall.com Mailing List