Answer in brief
CVE-2026-43374 records a Unknown severity vulnerability in net: nexthop: fix percpu use-after-free in remove_nh_grp_entry. 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 | >=f4676ea74b8549cd88dbfe2a592ce4530039e61f <abf4feaee6405f1441929c6ebe7a250f2cd170a7 || >=f4676ea74b8549cd88dbfe2a592ce4530039e61f <ab5ebab9664214ba41a7633cb4e72f128204f924 || >=f4676ea74b8549cd88dbfe2a592ce4530039e61f <9e08ad731862b22a87cc55f752e16d66cdc9e231 || >=f4676ea74b8549cd88dbfe2a592ce4530039e61f <b2662e7593e94ae09b1cf7ee5f09160a3612bcb2 | abf4feaee6405f1441929c6ebe7a250f2cd170a7, ab5ebab9664214ba41a7633cb4e72f128204f924, 9e08ad731862b22a87cc55f752e16d66cdc9e231, b2662e7593e94ae09b1cf7ee5f09160a3612bcb2 |
| Linux/Linuxgeneric | 6.9 | Not reported |
Published upstream
May 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: net: nexthop: fix percpu use-after-free in remove_nh_grp_entry When removing a nexthop from a group, remove_nh_grp_entry() publishes the new group via rcu_assign_pointer() then immediately frees the removed entry's percpu stats with free_percpu(). However, the synchronize_net() grace period in the caller remove_nexthop_from_groups() runs after the free. RCU readers that entered before the publish still see the old group and can dereference the freed stats via nh_grp_entry_stats_inc() -> get_cpu_ptr(nhge->stats), causing a use-after-free on percpu memory. Fix by deferring the free_percpu() until after synchronize_net() in the caller. Removed entries are chained via nh_list onto a local deferred free list. After the grace period completes and all RCU readers have finished, the percpu stats are safely freed.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-43374 records a Unknown severity vulnerability in net: nexthop: fix percpu use-after-free in remove_nh_grp_entry. 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 | >=f4676ea74b8549cd88dbfe2a592ce4530039e61f <abf4feaee6405f1441929c6ebe7a250f2cd170a7 || >=f4676ea74b8549cd88dbfe2a592ce4530039e61f <ab5ebab9664214ba41a7633cb4e72f128204f924 || >=f4676ea74b8549cd88dbfe2a592ce4530039e61f <9e08ad731862b22a87cc55f752e16d66cdc9e231 || >=f4676ea74b8549cd88dbfe2a592ce4530039e61f <b2662e7593e94ae09b1cf7ee5f09160a3612bcb2 | abf4feaee6405f1441929c6ebe7a250f2cd170a7, ab5ebab9664214ba41a7633cb4e72f128204f924, 9e08ad731862b22a87cc55f752e16d66cdc9e231, b2662e7593e94ae09b1cf7ee5f09160a3612bcb2 |
| Linux/Linuxgeneric | 6.9 | Not reported |
Published upstream
May 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: net: nexthop: fix percpu use-after-free in remove_nh_grp_entry When removing a nexthop from a group, remove_nh_grp_entry() publishes the new group via rcu_assign_pointer() then immediately frees the removed entry's percpu stats with free_percpu(). However, the synchronize_net() grace period in the caller remove_nexthop_from_groups() runs after the free. RCU readers that entered before the publish still see the old group and can dereference the freed stats via nh_grp_entry_stats_inc() -> get_cpu_ptr(nhge->stats), causing a use-after-free on percpu memory. Fix by deferring the free_percpu() until after synchronize_net() in the caller. Removed entries are chained via nh_list onto a local deferred free list. After the grace period completes and all RCU readers have finished, the percpu stats are safely freed.
Quoted source text, attributed separately from HOL analysis.