Answer in brief
CVE-2026-72254 records a High severity (CVSS 7.5) vulnerability in netfilter: nft_fib: reject fib expression on the netdev egress hook. 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.
CVSS is 7.5. 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 | >=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <4fee43759b489559a491f7c95f9bfa7a1d0c7a10 || >=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <568931f26af4727a51e8521f72efbc78d3b82410 || >=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <d01c913febead04a01a5f3a6374d1f45504dc523 || >=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <f68305267ebda7e839b5e8f77e8d77535a3d5a0f || >=42df6e1d221dddc0f2acf2be37e68d553ad65f96 <d07955dd34ecae17d35d8c7d0a273a3fba653a8c | 4fee43759b489559a491f7c95f9bfa7a1d0c7a10, 568931f26af4727a51e8521f72efbc78d3b82410, d01c913febead04a01a5f3a6374d1f45504dc523, f68305267ebda7e839b5e8f77e8d77535a3d5a0f, d07955dd34ecae17d35d8c7d0a273a3fba653a8c |
| Linux/Linuxgeneric | 5.16 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 15, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_fib: reject fib expression on the netdev egress hook A fib expression in a netdev egress base chain dereferences nft_in(pkt), NULL on the transmit path, causing a NULL pointer dereference at eval. nft_fib_validate() masks the hook with NF_INET_* values, but netdev hook numbers are a separate enum that aliases them (NF_NETDEV_EGRESS == NF_INET_LOCAL_IN), so an egress chain passes validation and then faults. Add nft_fib_netdev_validate() that limits each result/flag to the netdev hook where the device it reads exists: the input-device cases (OIF, OIFNAME, ADDRTYPE with F_IIF) to ingress, the output-device case (ADDRTYPE with F_OIF) to egress, ADDRTYPE with no device flag to both. Also restrict nft_fib_validate() to NFPROTO_IPV4/IPV6/INET so its NF_INET_* masks are not applied to another family's hooks.
Quoted source text, attributed separately from HOL analysis.