Answer in brief
CVE-2026-31684 records a Unknown severity vulnerability in net: sched: act_csum: validate nested VLAN headers. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | 5.1 | Not reported |
| Linux/Linuxgeneric | >=2ecba2d1e45b24620a7c3df9531895cf68d5dec6 <0410c619e86551677fb79887a38eccad3f5a0725 || >=2ecba2d1e45b24620a7c3df9531895cf68d5dec6 <886469b6455611a511aa6013e957e15e50577513 || >=2ecba2d1e45b24620a7c3df9531895cf68d5dec6 <46c07ad50fa2f4ba7663ee1b72b75ad7ad45cf09 || >=2ecba2d1e45b24620a7c3df9531895cf68d5dec6 <eb3765b90eb8f2a3d6310a80c14a9e57ec4267a2 || >=2ecba2d1e45b24620a7c3df9531895cf68d5dec6 <a69738efea0996d05a3c7d2178551b891744df1b || >=2ecba2d1e45b24620a7c3df9531895cf68d5dec6 <ec4930979b3f7bbeb7af5744599fc6603a4dba62 || >=2ecba2d1e45b24620a7c3df9531895cf68d5dec6 <3d165d975305cf76ff0b10a3c798fb31e5f5f9a5 || >=2ecba2d1e45b24620a7c3df9531895cf68d5dec6 <c842743d073bdd683606cb414eb0ca84465dd834 || 3764bfae5056e95617b6ee074129297e11710886 || >=4.19.99 <4.20 | 0410c619e86551677fb79887a38eccad3f5a0725, 886469b6455611a511aa6013e957e15e50577513, 46c07ad50fa2f4ba7663ee1b72b75ad7ad45cf09, eb3765b90eb8f2a3d6310a80c14a9e57ec4267a2, a69738efea0996d05a3c7d2178551b891744df1b, ec4930979b3f7bbeb7af5744599fc6603a4dba62, 3d165d975305cf76ff0b10a3c798fb31e5f5f9a5, c842743d073bdd683606cb414eb0ca84465dd834, 4.20 |
Published upstream
Apr 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 6, 2026
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.
Quoted source text, attributed separately from HOL analysis.