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.

CVSS

7.8

EPSS

0.102 (95.7th percentile)

CISA KEV

Added 2026-10-28, due 2026-10-31

Exploitation

active

Public exploits

15 repositories

State

PUBLISHED

Coverage

• ● Actively exploitedCritical 95CISA advisories & alerts◆Authoritative. Authoritative publisher: a primary source, or a newsroom with formal editorial standards28 Oct, 12:00

  CISA Adds Two Known Exploited Vulnerabilities to Catalog

  CISA has added two new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog, based on evidence of active exploitation. CVE-2026-41709 Broadcom VMWare ESX Insufficient Logging Vulnerability CVE-2026-46300 Linux Kernel Missing Initialization of a Variable Vulnerability These types of…

  ↗cisa.gov/news-events/alerts/2026/10/28/cisa-add…(opens the publisher's site in a new tab)

What we observed

1. 28 Oct, 19:50poc publishedpoc-in-github
2. 28 Oct, 19:50kev addedcisa-kev