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NVD / CVE Program· CNA Linux

CVE-2026-46300: net: skbuff: preserve shared-frag marker during coalescing

Noroxi assessment

Priority: This week (action score 66/100)

  • CISA has confirmed exploitation in the wild (Oct 28, 2026). Remediation deadline for US federal agencies: Oct 31, 2026.
  • A ready-made attack module is public (Metasploit); exploiting it takes no special expertise.
  • Probability of exploitation in the next 30 days: 16.1% (FIRST EPSS); higher than 96.9% of all records.
  • This probability rose by 14 points in the last 7 days.
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c, 3599e6b3cc1ada96883d496a50a210d3afbb6987, 3884358a9286b17f389a72b1426fc4547c23c111; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.141.1-1.

Don’t wait for the next maintenance window. Upgrade to Linux Linux 2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c, 3599e6b3cc1ada96883d496a50a210d3afbb6987, 3884358a9286b17f389a72b1426fc4547c23c111; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.141.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

HighCVSS 7.8 · v3.1KEVWeaponized Fix available
Published
May 23, 2026
Updated
Oct 29, 2026
EPSS
16.1% · 96th percentile▲ 14

Report tools

JSON

Action score

66

This week

Don’t wait for the next maintenance window.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
30 / 30 · Listed
EPSS
5 / 30 · 16.1%

CISA SSVC decision

Exploitation
active
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.8
CNA · Linux
7.8
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Oct 28, 2026. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Oct 31, 2026.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-46300

When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel
siemenssimatic s7-1500 cpu 1518-4 pn/dp mfp firmware
siemenssimatic s7-1500 cpu 1518-4 pn/dp mfp
redhatopenshift container platform
redhatenterprise linux
redhatenterprise linux aus
redhatenterprise linux eus
redhatenterprise linux tus
redhatenterprise linux update services for sap solutions

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.19 and later · before 7.0.10
  • linux linux kernel3.9 and later · up to 5.10.257 inclusive
  • linux linux kernel5.11 and later · before 5.15.208
  • linux linux kernel5.16 and later · before 6.1.174
  • linux linux kernel6.2 and later · before 6.6.141
  • linux linux kernel6.7 and later · before 6.12.91
  • linux linux kernel6.13 and later · before 6.18.33
  • linux linux kernel7.1
  • redhat enterprise linux10.0
  • redhat enterprise linux6.0
  • redhat enterprise linux7.0
  • redhat enterprise linux8.0
  • redhat enterprise linux9.0
  • redhat enterprise linux aus8.4
  • redhat enterprise linux aus8.6
  • redhat enterprise linux eus10.0
  • redhat enterprise linux eus8.4
  • redhat enterprise linux eus9.4
  • redhat enterprise linux eus9.6
  • redhat enterprise linux tus8.6

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 3.9affected
    • cef401de7be8c4e155c6746bfccf721a4fa5fab9 and later · before 3599e6b3cc1ada96883d496a50a210d3afbb6987affected · git
    • cef401de7be8c4e155c6746bfccf721a4fa5fab9 and later · before 2f2b16022a2e10ca7bccfb98db5ed2ec0f72641caffected · git
    • cef401de7be8c4e155c6746bfccf721a4fa5fab9 and later · before 9d3e5fd19fe1063bf607219e8562fbd567b8e8d5affected · git
    • cef401de7be8c4e155c6746bfccf721a4fa5fab9 and later · before 78bf6b6bb19541d19fbda6242e7cfe2c682763c0affected · git
    • cef401de7be8c4e155c6746bfccf721a4fa5fab9 and later · before 760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34eaffected · git
    • cef401de7be8c4e155c6746bfccf721a4fa5fab9 and later · before 3bd9e113d50034db99d7ef69fd8e5242d15e414aaffected · git
    • cef401de7be8c4e155c6746bfccf721a4fa5fab9 and later · before 3884358a9286b17f389a72b1426fc4547c23c111affected · git
    • cef401de7be8c4e155c6746bfccf721a4fa5fab9 and later · before f84eca5817390257cef78013d0112481c503b4a3affected · git
    • before 3.9not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-124.56.5.el10_16.12.0-124.56.5.el10_1
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.16.1.el10_26.12.0-211.16.1.el10_2

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-43502May 21, 2026 · net/rds: handle zerocopy send cleanup before the message is queued
    31Monitor
  • ← EarlierCVE-2026-43503May 23, 2026 · net: skbuff: propagate shared-frag marker through frag-transfer helpers
    40Plan
  • Later →CVE-2026-45834May 26, 2026 · Bluetooth: L2CAP: Fix null-ptr-deref in l2cap_sock_state_change_cb()
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux2f2b16022a2e10ca7bccfb98db5ed2ec0f72641cVendor (CNA)
Linux Linux3599e6b3cc1ada96883d496a50a210d3afbb6987Vendor (CNA)
Linux Linux3884358a9286b17f389a72b1426fc4547c23c111Vendor (CNA)
Linux Linux3bd9e113d50034db99d7ef69fd8e5242d15e414aVendor (CNA)
Linux Linux760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34eVendor (CNA)
Linux Linux78bf6b6bb19541d19fbda6242e7cfe2c682763c0Vendor (CNA)
Linux Linux9d3e5fd19fe1063bf607219e8562fbd567b8e8d5Vendor (CNA)
Linux Linuxf84eca5817390257cef78013d0112481c503b4a3Vendor (CNA)
azl3 kernel 6.6.139.1-1 on Azure Linux 3.06.6.141.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:kernel5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel-matched5.14.0-687.10.1.el9_8 · AlmaLinux:9Package registry (OSV)
debian:linux6.1.174-1 · Debian:12Package registry (OSV)
red hat:kernel0:5.14.0-570.116.1.el9_6 · Red Hat:openshift:4.21::el9Package registry (OSV)
red hat:kernel-64k0:5.14.0-570.116.1.el9_6 · Red Hat:openshift:4.21::el9Package registry (OSV)
red hat:kernel-64k-core0:5.14.0-570.116.1.el9_6 · Red Hat:openshift:4.21::el9Package registry (OSV)
red hat:kernel-64k-debug0:5.14.0-570.116.1.el9_6 · Red Hat:openshift:4.21::el9Package registry (OSV)
red hat:kernel-64k-debug-core0:5.14.0-570.116.1.el9_6 · Red Hat:openshift:4.21::el9Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-570.116.1.el9_6 · Red Hat:openshift:4.21::el9Package registry (OSV)
red hat:openshift0:4.21.0-202605142021.p2.geab2218.assembly.stream.el10 · Red Hat:openshift:4.21::el10Package registry (OSV)
red hat:openshift-hyperkube0:4.21.0-202605142021.p2.geab2218.assembly.stream.el10 · Red Hat:openshift:4.21::el10Package registry (OSV)

+18

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Exploit-DB entry ×1
  • Proof-of-concept repository on GitHub ×15

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Exploit-DB entrylocal2026-05-29
Metasploit moduleexploit/linux/local/cve_2026_46300_fragnesiaFragnesia LPE (CVE-2026-46300)exploit2026-05-14
Proof-of-concept repository on GitHubstars:22026-05-14
Proof-of-concept repository on GitHubstars:12026-05-14
Proof-of-concept repository on GitHubstars:162026-05-15
Proof-of-concept repository on GitHubstars:02026-05-17
Proof-of-concept repository on GitHubstars:02026-05-18
Proof-of-concept repository on GitHubstars:02026-05-20
Proof-of-concept repository on GitHubstars:02026-05-20
Proof-of-concept repository on GitHubstars:02026-06-01
Proof-of-concept repository on GitHubstars:02026-06-02
Proof-of-concept repository on GitHubstars:12026-06-03

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-10 d
  2. Metasploit-10 d
  3. Published
  4. CISA KEV+157 d
  5. TodayOct 31, 2026+161 d
EPSS, last 120 days+14% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. KEV✗ → ✓
  2. SSVC exploitationnone → active
  3. SSVC exploitation— → none
  4. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (19 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records