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().

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-1515 advisory.

    In the Linux kernel, the following vulnerability has been resolved:

    audit: add fchmodat2() to change attributes class (CVE-2025-71239)

    In the Linux kernel, the following vulnerability has been resolved:

    fs: ntfs3: fix infinite loop in attr_load_runs_range on inconsistent metadata (CVE-2025-71265)

    In the Linux kernel, the following vulnerability has been resolved:

    fs: ntfs3: check return value of indx_find to avoid infinite loop (CVE-2025-71266)

    In the Linux kernel, the following vulnerability has been resolved:

    fs: ntfs3: fix infinite loop triggered by zero-sized ATTR_LIST (CVE-2025-71267)

    In the Linux kernel, the following vulnerability has been resolved:

    espintcp: Fix race condition in espintcp_close() (CVE-2026-23239)

    In the Linux kernel, the following vulnerability has been resolved:

    tls: Fix race condition in tls_sw_cancel_work_tx() (CVE-2026-23240)

    In the Linux kernel, the following vulnerability has been resolved:

    audit: add missing syscalls to read class (CVE-2026-23241)

    In the Linux kernel, the following vulnerability has been resolved:

    xfs: check for deleted cursors when revalidating two btrees (CVE-2026-23249)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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().
    (CVE-2026-23240)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
304620	Amazon Linux 2023 : bpftool6.18, kernel6.18, kernel6.18-devel (ALAS2023-2026-1515)	Nessus	Amazon Linux Local Security Checks	medium
301793	Linux Distros Unpatched Vulnerability : CVE-2026-23240	Nessus	Misc.	medium

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CVE-2026-23240

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Tenable Plugins

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medium