CVE-2026-46300
net: skbuff: preserve shared-frag marker during coalescing
- Published
- May 23, 2026
- Updated
- Oct 16, 2026
- Assigning CNA
- Linux
- Evidence observed
- May 29, 2026
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLow · next 30 days
- Percentile
- 83.9%
- Model date
- Oct 17, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
Summary
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.
Sources
modules/exploits/linux/local/cve_2026_46300_fragnesia.rb
Metasploit Framework modulesDeclared conditions
- platform: Linux,Unix($.exploit_linux/local/cve_2026_46300_fragnesia.platform)
- verification: check_declared($.exploit_linux/local/cve_2026_46300_fragnesia.check)
Responsible use
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