Answer in brief
CVE-2026-23440 records a High severity (CVSS 7.5) vulnerability in net/mlx5e: Fix race condition during IPSec ESN update. 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 | >=fef06678931ff67b158d337b581e5cf5ca40a3a3 <3dffc083292e6872787bd7e34b957627622f9af4 || >=fef06678931ff67b158d337b581e5cf5ca40a3a3 <2051c709dce92da3550040aa7949cd5a9c89b14e || >=fef06678931ff67b158d337b581e5cf5ca40a3a3 <96c9c25b74686ac2de15921c9ad30c5ef13af8cd || >=fef06678931ff67b158d337b581e5cf5ca40a3a3 <8d625c15471fb8780125eaef682983a96af77bdc || >=fef06678931ff67b158d337b581e5cf5ca40a3a3 <beb6e2e5976a128b0cccf10d158124422210c5ef | 3dffc083292e6872787bd7e34b957627622f9af4, 2051c709dce92da3550040aa7949cd5a9c89b14e, 96c9c25b74686ac2de15921c9ad30c5ef13af8cd, 8d625c15471fb8780125eaef682983a96af77bdc, beb6e2e5976a128b0cccf10d158124422210c5ef |
| Linux/Linuxgeneric | 6.4 | Not reported |
Published upstream
Apr 3, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 16, 2026
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix race condition during IPSec ESN update In IPSec full offload mode, the device reports an ESN (Extended Sequence Number) wrap event to the driver. The driver validates this event by querying the IPSec ASO and checking that the esn_event_arm field is 0x0, which indicates an event has occurred. After handling the event, the driver must re-arm the context by setting esn_event_arm back to 0x1. A race condition exists in this handling path. After validating the event, the driver calls mlx5_accel_esp_modify_xfrm() to update the kernel's xfrm state. This function temporarily releases and re-acquires the xfrm state lock. So, need to acknowledge the event first by setting esn_event_arm to 0x1. This prevents the driver from reprocessing the same ESN update if the hardware sends events for other reason. Since the next ESN update only occurs after nearly 2^31 packets are received, there's no risk of missing an update, as it will happen long after this handling has finished. Processing the event twice causes the ESN high-order bits (esn_msb) to be incremented incorrectly. The driver then programs the hardware with this invalid ESN state, which leads to anti-replay failures and a complete halt of IPSec traffic. Fix this by re-arming the ESN event immediately after it is validated, before calling mlx5_accel_esp_modify_xfrm(). This ensures that any spurious, duplicate events are correctly ignored, closing the race window.
Quoted source text, attributed separately from HOL analysis.