CVE-2026-31684

Aliases:UBUNTU-CVE-2026-31684DEBIAN-CVE-2026-31684CGA-c52c-4x6f-3j5vCGA-hf8h-f8xq-4fvxCGA-hfhg-wxjr-f7m7CGA-jg46-qm76-xm97CGA-jr5c-693r-xqfxCGA-wf34-56vj-5jp6
Advisory lineage Upstream: 0 Downstream: 32
Modified
Published: 25 Apr 2026, 08:47
Last modified:01 Jun 2026, 16:13

Vulnerability Summary

Overall Risk (default)
low
22/100
CVSS Score
5.5 MEDIUM
v3.1 (nvd)
EPSS Score
0.12% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

25 Apr 2026, 08:47
Published
Vulnerability first disclosed
01 Jun 2026, 16:13
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: net: sched: act_csum: validate nested VLAN headers tcf_csum_act() walks nested VLAN headers directly from skb->data when an skb still carries in-payload VLAN tags. The current code reads vlan->h_vlan_encapsulated_proto and then pulls VLAN_HLEN bytes without first ensuring that the full VLAN header is present in the linear area. If only part of an inner VLAN header is linearized, accessing h_vlan_encapsulated_proto reads past the linear area, and the following skb_pull(VLAN_HLEN) may violate skb invariants. Fix this by requiring pskb_may_pull(skb, VLAN_HLEN) before accessing and pulling each nested VLAN header. If the header still is not fully available, drop the packet through the existing error path.

CVSS Metrics

  • v3.1MEDIUMScore: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.12% Percentile: 2%

Affected Systems

  • chainguardlinux-aws-6.18

    < 6.18.31-r0

  • chainguardlinux-azure-6.18

    < 6.18.24-r1 | < 6.18.31-r0

  • chainguardlinux-gcp-6.18

    < 6.18.31-r0

  • chainguardlinux-qemu-6.18

    < 6.18.24-r3

  • chainguardlinux-vmware-6.18

    < 6.18.31-r0

  • debianlinux

    < 5.10.259-1 | < 6.1.176-1 | < 6.12.85-1 | < 6.19.14-1

  • debianlinux-6.1

    < 6.1.176-1~deb11u1

  • ubuntulinux

    all | < 5.15.0-186.196 | < 6.8.0-136.136 | all

  • ubuntulinux-allwinner-5.19

    all

  • ubuntulinux-aws

    all | < 5.15.0-1112.119 | < 6.8.0-1061.64 | all

  • ubuntulinux-aws-5.0

    all

  • ubuntulinux-aws-5.11

    all

  • ubuntulinux-aws-5.13

    all

  • ubuntulinux-aws-5.15

    < 5.15.0-1112.119~20.04.1

  • ubuntulinux-aws-5.19

    all

  • ubuntulinux-aws-5.3

    all

  • ubuntulinux-aws-5.4

    all

  • ubuntulinux-aws-5.8

    all

  • ubuntulinux-aws-6.14

    all

  • ubuntulinux-aws-6.17

    all

  • ubuntulinux-aws-6.2

    all

  • ubuntulinux-aws-6.5

    all

  • ubuntulinux-aws-6.8

    < 6.8.0-1061.64~22.04.1

  • ubuntulinux-aws-fips

    all | < 5.15.0-1112.119+fips1 | < 6.8.0-1061.64+fips1

  • ubuntulinux-azure

    all | all | < 5.15.0-1117.126 | < 6.8.0-1063.71 | all

  • ubuntulinux-azure-5.11

    all

  • ubuntulinux-azure-5.13

    all

  • ubuntulinux-azure-5.15

    < 5.15.0-1117.126~20.04.1

  • ubuntulinux-azure-5.19

    all

  • ubuntulinux-azure-5.3

    all

  • ubuntulinux-azure-5.4

    all

  • ubuntulinux-azure-5.8

    all

  • ubuntulinux-azure-6.11

    all

  • ubuntulinux-azure-6.14

    all

  • ubuntulinux-azure-6.17

    all

  • ubuntulinux-azure-6.2

    all

  • ubuntulinux-azure-6.5

    all

  • ubuntulinux-azure-6.8

    < 6.8.0-1063.71~22.04.1

  • ubuntulinux-azure-edge

    all

  • ubuntulinux-azure-fde

    all | < 5.15.0-1117.126 | < 6.8.0-1062.69 | all | all

  • ubuntulinux-azure-fde-5.15

    < 5.15.0-1117.126~20.04.2

  • ubuntulinux-azure-fde-5.19

    all

  • ubuntulinux-azure-fde-6.14

    all

  • ubuntulinux-azure-fde-6.2

    all

  • ubuntulinux-azure-fde-6.8

    < 6.8.0-1062.69~22.04.1

  • ubuntulinux-azure-fde-7.0

    all

  • ubuntulinux-azure-fips

    all | < 5.15.0-1117.126+fips1 | < 6.8.0-1063.71+fips2

  • ubuntulinux-azure-nvidia

    all

  • ubuntulinux-azure-nvidia-6.14

    all

  • ubuntulinux-bluefield

    all | all | < 5.15.0-1096.98 | < 6.8.0-1028.33

Showing first 50 affected entries in server-rendered view.

References (38)