CVE-2026-23240

Critical

Description

In the Linux kernel, the following vulnerability has been resolved: tls: Fix race condition in tls_sw_cancel_work_tx() This issue was discovered during a code audit. After cancel_delayed_work_sync() is called from tls_sk_proto_close(), tx_work_handler() can still be scheduled from paths such as the Delayed ACK handler or ksoftirqd. As a result, the tx_work_handler() worker may dereference a freed TLS object. The following is a simple race scenario: cpu0 cpu1 tls_sk_proto_close() tls_sw_cancel_work_tx() tls_write_space() tls_sw_write_space() if (!test_and_set_bit(BIT_TX_SCHEDULED, &tx_ctx->tx_bitmask)) set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask); cancel_delayed_work_sync(&ctx->tx_work.work); schedule_delayed_work(&tx_ctx->tx_work.work, 0); To prevent this race condition, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync().

SeverityCritical
CVSS9.8
Exploit probability—
ProductLinux Kernel
PublishedMar 10, 2026
First seenMar 10, 2026

How to fix

Update
  • linux linux_kernel6.12.75, 6.18.16, 6.19.6 or later

Affected products

ProductAffected versionsFixed in
linux linux_kernel5.3.1 ≤ v < 6.12.75, 6.13 ≤ v < 6.18.16, 6.19 ≤ v < 6.19.6, 5.3, 7.06.12.75, 6.18.16, 6.19.6

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CVE-2026-23240 · Linux Kernel · Dark Radar