Answer in brief
CVE-2026-72493 records a Unknown severity vulnerability in net: serialize netif_running() check in enqueue_to_backlog(). 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 | >=e9e4dd3267d0c5234c5c0f47440456b10875dec9 <2fface6e0bbd6314d1d9d071abf2c4d67548511c || >=e9e4dd3267d0c5234c5c0f47440456b10875dec9 <46762cefe7f4e5bffc1eb467810a7bbb02e461d7 || 78b6803a1961369d0b8350ff1f99b7375bbd7a8f || b5d73d9cdd6be22795499890ea928a6f57ef829c || f6533fed1bfa842e391ee50f9a9c5e963c71e579 || 2095ab2456da766174cda8bc105d7a7b1bc70e16 || f1fdb184aefa8447560e3ea0e605171592ffee41 || f75c8a3015422128ca150e81c730bc2a471b5f4a || >=3.2.71 <3.3 || >=3.4.111 <3.5 || >=3.12.48 <3.13 || >=3.14.54 <3.15 || >=3.18.22 <3.19 || >=4.1.9 <4.2 | 2fface6e0bbd6314d1d9d071abf2c4d67548511c, 46762cefe7f4e5bffc1eb467810a7bbb02e461d7, 3.3, 3.5, 3.13, 3.15, 3.19, 4.2 |
| Linux/Linuxgeneric | 4.2 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 15, 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: net: serialize netif_running() check in enqueue_to_backlog() Syzbot reported a KASAN slab-use-after-free in fib_rules_lookup(). The root cause is a race condition where packets can escape the backlog flushing during device unregistration (e.g., during netns exit). Commit e9e4dd3267d0 ("net: do not process device backlog during unregistration") introduced a lockless netif_running() check in enqueue_to_backlog() to prevent queuing packets to an unregistering device. However, this creates a TOCTOU race window. A lockless transmitter (like veth_xmit) can pass the check before dev_close() clears IFF_UP. If the transmitter is then delayed, flush_all_backlogs() can run and finish before the transmitter grabs the backlog lock and queues the packet. The packet then escapes the flush and triggers UAF later when processed. Fix this by moving the netif_running() check inside the backlog lock. This serializes the check with the flush work (which also grabs the lock). We then either queue the packet before the flush runs (so it gets flushed), or check netif_running() after the flush/close completes (so it gets dropped).
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-72493 records a Unknown severity vulnerability in net: serialize netif_running() check in enqueue_to_backlog(). 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 | >=e9e4dd3267d0c5234c5c0f47440456b10875dec9 <2fface6e0bbd6314d1d9d071abf2c4d67548511c || >=e9e4dd3267d0c5234c5c0f47440456b10875dec9 <46762cefe7f4e5bffc1eb467810a7bbb02e461d7 || 78b6803a1961369d0b8350ff1f99b7375bbd7a8f || b5d73d9cdd6be22795499890ea928a6f57ef829c || f6533fed1bfa842e391ee50f9a9c5e963c71e579 || 2095ab2456da766174cda8bc105d7a7b1bc70e16 || f1fdb184aefa8447560e3ea0e605171592ffee41 || f75c8a3015422128ca150e81c730bc2a471b5f4a || >=3.2.71 <3.3 || >=3.4.111 <3.5 || >=3.12.48 <3.13 || >=3.14.54 <3.15 || >=3.18.22 <3.19 || >=4.1.9 <4.2 | 2fface6e0bbd6314d1d9d071abf2c4d67548511c, 46762cefe7f4e5bffc1eb467810a7bbb02e461d7, 3.3, 3.5, 3.13, 3.15, 3.19, 4.2 |
| Linux/Linuxgeneric | 4.2 | Not reported |
Published upstream
Aug 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 15, 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: net: serialize netif_running() check in enqueue_to_backlog() Syzbot reported a KASAN slab-use-after-free in fib_rules_lookup(). The root cause is a race condition where packets can escape the backlog flushing during device unregistration (e.g., during netns exit). Commit e9e4dd3267d0 ("net: do not process device backlog during unregistration") introduced a lockless netif_running() check in enqueue_to_backlog() to prevent queuing packets to an unregistering device. However, this creates a TOCTOU race window. A lockless transmitter (like veth_xmit) can pass the check before dev_close() clears IFF_UP. If the transmitter is then delayed, flush_all_backlogs() can run and finish before the transmitter grabs the backlog lock and queues the packet. The packet then escapes the flush and triggers UAF later when processed. Fix this by moving the netif_running() check inside the backlog lock. This serializes the check with the flush work (which also grabs the lock). We then either queue the packet before the flush runs (so it gets flushed), or check netif_running() after the flush/close completes (so it gets dropped).
Quoted source text, attributed separately from HOL analysis.