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VulnerabilityPublished Updated

CVE-2026-46323: Linux kernel · net: gro: don't merge zcopy skbs

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in e334cbf3388fd9334503a778a82d9e9f14dd2f71 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in e334cbf3388fd9334503a778a82d9e9f14dd2f71, 479084ae0e1d9cb7929cb4298d35623de189f80a, 44bea2032af0425e4ce6d26a8af0ede79db49ec1 +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 9 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 753f1ca4e1e50248a1b760c9774d6d6b354562cc, < e334cbf3388fd9334503a778a82d9e9f14dd2f71
Fixed in
  • e334cbf3388fd9334503a778a82d9e9f14dd2f71
LinuxLinuxAffected
  • ≥ 753f1ca4e1e50248a1b760c9774d6d6b354562cc, < 479084ae0e1d9cb7929cb4298d35623de189f80a
Fixed in
  • 479084ae0e1d9cb7929cb4298d35623de189f80a
LinuxLinuxAffected
  • ≥ 753f1ca4e1e50248a1b760c9774d6d6b354562cc, < 44bea2032af0425e4ce6d26a8af0ede79db49ec1
Fixed in
  • 44bea2032af0425e4ce6d26a8af0ede79db49ec1
LinuxLinuxAffected
  • ≥ 753f1ca4e1e50248a1b760c9774d6d6b354562cc, < 4db79a322db8c97f7b73b8a347395ef4d685eb40
Fixed in
  • 4db79a322db8c97f7b73b8a347395ef4d685eb40
LinuxLinuxAffected
  • ≥ 753f1ca4e1e50248a1b760c9774d6d6b354562cc, < 3c6cc9f2ca65b6dd61b1af75452dc0e1cd0aad8d
Fixed in
  • 3c6cc9f2ca65b6dd61b1af75452dc0e1cd0aad8d
LinuxLinuxAffected
  • ≥ 753f1ca4e1e50248a1b760c9774d6d6b354562cc, < 1f9c828556416fbe3f49386708ce999fc4d4da06
Fixed in
  • 1f9c828556416fbe3f49386708ce999fc4d4da06

Description

In the Linux kernel, the following vulnerability has been resolved: net: gro: don't merge zcopy skbs skb_gro_receive() can currently copy frags between the source and GRO skb, without checking the zerocopy status, and in particular the SKBFL_MANAGED_FRAG_REFS flag. When SKBFL_MANAGED_FRAG_REFS is set, the skb doesn't hold a reference on the pages in shinfo->frags. Appending those frags to another skb's frags without fixing up the page refcount can lead to UAF. When either the last skb in the GRO chain (the one we would append frags to) or the source skb is zerocopy, don't merge the skbs.

References

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