All vulnerabilities
CVE-2026-46300

Linux: net: skbuff: preserve shared-frag marker during coalescing

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
7.8High
ExploitationExploitation reportedCISA's assessment says active exploitation, assessed 28 Oct 2026. Not yet in the KEV catalogCISA via CVE List
Exploit odds (EPSS)10.2%Chance of exploitation activity in the next 30 days, higher than 95% of CVEs. Scored 28 Oct 2026FIRST EPSS
Fixed in3599e6b3cc1ada96883d496a50a210d3afbb6987Also 2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c, 9d3e5fd19fe1063bf607219e8562fbd567b8e8d5 and 4 moreCVE List
Published23 May 2026Updated 28 Oct 2026CVE List

What fixes it

  • 3599e6b3cc1ada96883d496a50a210d3afbb6987LinuxCVE List
  • 2f2b16022a2e10ca7bccfb98db5ed2ec0f72641cLinuxCVE List
  • 9d3e5fd19fe1063bf607219e8562fbd567b8e8d5LinuxCVE List
  • 78bf6b6bb19541d19fbda6242e7cfe2c682763c0LinuxCVE List
  • 760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34eLinuxCVE List
  • 3bd9e113d50034db99d7ef69fd8e5242d15e414aLinuxCVE List
Show all 7 fixed versions
  • 3884358a9286b17f389a72b1426fc4547c23c111LinuxCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 14 May 2026Exploit code publicMetasploit
  2. 23 May 2026, 11:44 UTCPublishedCVE List
  3. 28 Oct 2026, 12:00 UTCFirst reported exploitedCISA advisories
  4. NowNot on CISA's known exploited list yet

Vendor and government advisories 1

Vendors that say their products are affected, and agencies that issued alerts. Check each for the fixed release of the product you run.

Public exploit code and templates 2

  • Exploit moduleFragnesia LPE (CVE-2026-46300) 14 May 2026Metasploit
  • Local exploitLinux Kernel - Local Privilege Escalation 29 May 2026Exploit-DB

Listed so defenders can prioritize. Threatline links to the source and does not host exploit code.

Reports 4

2 outlets report exploitation. Reports are not confirmation; each links to its source.

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.

Text from CVE List

Affected versions 18

  • Linuxaffected: cef401de7be8c4e155c6746bfccf721a4fa5fab9 before 3599e6b3cc1ada96883d496a50a210d3afbb6987CVE List
  • Linuxaffected: cef401de7be8c4e155c6746bfccf721a4fa5fab9 before 2f2b16022a2e10ca7bccfb98db5ed2ec0f72641cCVE List
  • Linuxaffected: cef401de7be8c4e155c6746bfccf721a4fa5fab9 before 9d3e5fd19fe1063bf607219e8562fbd567b8e8d5CVE List
  • Linuxaffected: cef401de7be8c4e155c6746bfccf721a4fa5fab9 before 78bf6b6bb19541d19fbda6242e7cfe2c682763c0CVE List
  • Linuxaffected: cef401de7be8c4e155c6746bfccf721a4fa5fab9 before 760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34eCVE List
  • Linuxaffected: cef401de7be8c4e155c6746bfccf721a4fa5fab9 before 3bd9e113d50034db99d7ef69fd8e5242d15e414aCVE List
  • Linuxaffected: cef401de7be8c4e155c6746bfccf721a4fa5fab9 before 3884358a9286b17f389a72b1426fc4547c23c111CVE List
  • Linuxaffected: cef401de7be8c4e155c6746bfccf721a4fa5fab9 before f84eca5817390257cef78013d0112481c503b4a3CVE List
  • Linuxaffected: 3.9CVE List
  • Linuxunaffected: all versions before 3.9CVE List
  • Linuxunaffected: 5.10.257 through 5.10.*CVE List
  • Linuxunaffected: 5.15.208 through 5.15.*CVE List
  • Linuxunaffected: 6.1.174 through 6.1.*CVE List
  • Linuxunaffected: 6.6.141 through 6.6.*CVE List
  • Linuxunaffected: 6.12.91 through 6.12.*CVE List
  • Linuxunaffected: 6.18.33 through 6.18.*CVE List
  • Linuxunaffected: 7.0.10 through 7.0.*CVE List
  • Linuxunaffected: 7.1CVE List

References 47