What’s Vulnerable › Vulnerabilities

CVE-2025-40176: tls: wait for pending async decryptions if tls_strp_msg_hold fails

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-11-12 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: tls: wait for pending async decryptions if tls_strp_msg_hold fails Async decryption calls tls_strp_msg_hold to create a clone of the input skb to hold references to the memory it uses. If we fail to allocate that clone, proceeding with async decryption can lead to various issues (UAF on the skb, writing into userspace memory after the recv() call has returned). In this case, wait for all pending decryption requests.

Affected products

• Linux kernel: 6.0 — fixed in 6.18

How to fix

Upgrade to a fixed version: Linux kernel 6.18. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/39dec4ea3daf77f684308576baf483b55ca7f160
• https://git.kernel.org/stable/c/4fc109d0ab196bd943b7451276690fb6bb48c2e0
• https://git.kernel.org/stable/c/9f83fd0c179e0f458e824e417f9d5ad53443f685
• https://git.kernel.org/stable/c/b8a6ff84abbcbbc445463de58704686011edc8e1
• https://git.kernel.org/stable/c/c61d4368197d65c4809d9271f3b85325a600586a

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