# CVE-2026-46300 — Linux

> As of 2026-09-08, CVE-2026-46300 is a HIGH-severity vulnerability in Linux, CVSS v3.1 7.8, EPSS 2.4% (83.7th percentile). Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2026-46300, most recently “Q2 2026 Vulnerability and Exploit Landscape: Exploited AI-platform flaws (OpenClaw CVE-2026-25253, Dify CVE-2026-41948, Open WebUI CVE-2026-45386), Exchange CVE-2026-45501, and Linux kernel page-cache LPE exploit wave (Copy Fail, Dirty Frag)”.

**Last updated:** 2026-09-08

## What is 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.

The record classifies CVE-2026-46300 under weakness class [CWE-123](https://cwe.mitre.org/data/definitions/123.html). Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 150 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.8 — HIGH (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **EPSS (FIRST):** 2.4% probability of exploitation in the next 30 days, higher than 83.7% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 9.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-05-23, last modified 2026-09-08

## Is CVE-2026-46300 being exploited?

Weaponised exploit code for CVE-2026-46300 is publicly available. 11 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 39 in the Threadlinqs vulnerability feed.

- [0xBlackash/CVE-2026-46300](https://github.com/0xBlackash/CVE-2026-46300) (github)
- [MadExploits/CVE-2026-46300](https://github.com/MadExploits/CVE-2026-46300) (github)
- [HORKimhab/CVE-2026-46300](https://github.com/HORKimhab/CVE-2026-46300) (github)
- [azilRababe/CVE-2026-46300](https://github.com/azilRababe/CVE-2026-46300) (github)
- [Sentebale/CVE-2026-46300](https://github.com/Sentebale/CVE-2026-46300) (github)
- [1neptune/Fragnesia](https://github.com/1neptune/Fragnesia) (github)
- [ExploitEoom/CVE-2026-46300](https://github.com/ExploitEoom/CVE-2026-46300) (github)
- [First-John/cve_2026_frag_family_fix](https://github.com/First-John/cve_2026_frag_family_fix) (github)

## Affected products and versions

- [Linux](https://intel.threadlinqs.com/vendors/linux): Linux

## How to fix CVE-2026-46300

No vendor patch reference has been recorded for CVE-2026-46300 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-46300

2 tracked threats in the Threadlinqs corpus reference CVE-2026-46300, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Q2 2026 Vulnerability and Exploit Landscape: Exploited AI-platform flaws (OpenClaw CVE-2026-25253, Dify CVE-2026-41948, Open WebUI CVE-2026-45386), Exchange CVE-2026-45501, and Linux kernel page-cache LPE exploit wave (Copy Fail, Dirty Frag)](https://intel.threadlinqs.com/threat/TL-2026-3924) — HIGH · 2026-10-20
- [Linux Kernel LPE Surge: Copy Fail (CVE-2026-31431), Dirty Frag/Fragnesia (CVE-2026-43284/CVE-2026-43500/CVE-2026-46300), and CrackArmor AppArmor Flaws vs. Defense-in-Depth Mitigations](https://intel.threadlinqs.com/threat/TL-2026-2424) — HIGH · 2026-05-29

## Sources

Enriched from CVE.org, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-10-10.

**Other references**

- [git.kernel.org](https://git.kernel.org/stable/c/3599e6b3cc1ada96883d496a50a210d3afbb6987)
- [git.kernel.org (2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c)](https://git.kernel.org/stable/c/2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c)
- [git.kernel.org (9d3e5fd19fe1063bf607219e8562fbd567b8e8d5)](https://git.kernel.org/stable/c/9d3e5fd19fe1063bf607219e8562fbd567b8e8d5)
- [git.kernel.org (78bf6b6bb19541d19fbda6242e7cfe2c682763c0)](https://git.kernel.org/stable/c/78bf6b6bb19541d19fbda6242e7cfe2c682763c0)
- [git.kernel.org (760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34e)](https://git.kernel.org/stable/c/760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34e)

_Showing 5 of 8 recorded references._

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-46300
Full detection coverage and IOCs for threats exploiting CVE-2026-46300 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp