CVE-2026-31684

MEDIUM EPSS 1.9%
Published Apr 25, 20262mo ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Apr 25, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

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 Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
1.9% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 12

VendorProductVersionRange
linuxlinux_kernel*≥4.19.99  –  <4.20
linuxlinux_kernel*≥5.1  –  <6.6.136
linuxlinux_kernel*≥6.7  –  <6.12.83
linuxlinux_kernel*≥6.13  –  <6.18.24
linuxlinux_kernel*≥6.19  –  <6.19.14
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any

References 8

  • git.kernel.org https://git.kernel.org/stable/c/0410c619e86551677fb79887a38eccad3f5a0725
  • git.kernel.org https://git.kernel.org/stable/c/3d165d975305cf76ff0b10a3c798fb31e5f5f9a5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/46c07ad50fa2f4ba7663ee1b72b75ad7ad45cf09
  • git.kernel.org https://git.kernel.org/stable/c/886469b6455611a511aa6013e957e15e50577513
  • git.kernel.org https://git.kernel.org/stable/c/a69738efea0996d05a3c7d2178551b891744df1b
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c842743d073bdd683606cb414eb0ca84465dd834
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/eb3765b90eb8f2a3d6310a80c14a9e57ec4267a2
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ec4930979b3f7bbeb7af5744599fc6603a4dba62
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/3d165d975305cf76ff0b10a3c798fb31e5f5f9a5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a69738efea0996d05a3c7d2178551b891744df1b
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c842743d073bdd683606cb414eb0ca84465dd834
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/eb3765b90eb8f2a3d6310a80c14a9e57ec4267a2
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ec4930979b3f7bbeb7af5744599fc6603a4dba62
    Patch