Summary
generated automatically from NVD dataIn the Linux kernel, skb_try_coalesce() in the networking stack failed to preserve the SKBFL_SHARED_FRAG marker when moving paged frags between skbs. Because TCP receive coalescing could produce an unmarked skb, ESP input might see skb_has_shared_frag() as false and decrypt in place over page-cache backed frags, causing an out-of-bounds write (CWE-787). The flaw is rated HIGH (CVSS v3.1 score 7.8) and is listed in the CISA KEV catalog as exploited.
NVD 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.
⚠️ Actively exploited — CISA KEV
This CVE was added to CISA's Known Exploited Vulnerabilities catalog on 2026-10-28. It is confirmed exploited in the wild and must be patched as a priority.
Remediation deadline (US federal agencies): 2026-10-31
EPSS · FIRST.org
10.2%probability of exploitation in the next 30 days
Higher than 95% of scored CVEs
EPSS (Exploit Prediction Scoring System) estimates, from observed exploitation activity, how likely a CVE is to be exploited in the next 30 days. It complements CVSS, which measures severity, not likelihood. Score of 2026-10-28, recomputed daily by FIRST.org.
In-depth analysis on cveo.tech
This CVE is covered in an article: context, affected versions and published fixes.
CVSS v3.1 Score
Information
- Published
- 23 mai 2026
- Updated
- 29 oct. 2026
- Status
- Undergoing Analysis
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected products
Bounds published by NVD: "< 8.4.27" means 8.4.27 is no longer vulnerable. The fixed release to install is in the vendor advisory.
Weaknesses (CWE)
References (51)
- + 36 more references on NVD
Similar CVEs
Other vulnerabilities of type CWE-787
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