CVE-2026-46331
EPSS 0.2%Real vuln, public patch, but low EPSS, no KEV, and sensational framing dominate chatter.
What: Linux kernel net/sched pedit (packet editing) Copy-on-Write logic flaw allows local privilege escalation via page cache corruption (CVE-2026-46331, EPSS 0.29%).
Why it matters: Social chatter claims public PoC and root exploitation; however, CVE is not KEV-listed, CVSS unassigned, and EPSS extremely low (0.20 percentile). Patch merged upstream early June 2026. No vendor advisories or defender triage signals detected—mostly blog/news amplification using dramatic language ("one-click root," "critical"). Actual risk appears overstated in sensational coverage.
Where it's seen: Tech news outlets and security bloggers republishing the kernel commit with inflated threat claims; platform engineers (Replit) noting their minimal kernel is unaffected; kernel developers discussing the late-May upstream fix.
RISK: MODERATE — Local LPE in kernel network subsystem; patch available; no KEV listing or mass exploitation signals.
Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: fix pedit partial COW leading to page cache corruption tcf_pedit_act() computes the COW range for skb_ensure_writable() once before the key loop using tcfp_off_max_hint, but the hint does not account for the runtime header offset added by typed keys. This can leave part of the write region un-COW'd. Fix by moving skb_ensure_writable() inside the per-key loop where the actual write offset is known, and add overflow checking on the offset arithmetic. For negative offsets (e.g. Ethernet header edits at ingress), use skb_cow() to COW the headroom instead. Guard offset_valid() against INT_MIN, where negation is undefined.