CVE-2026-74611 tls: rx: restore msg_iter before TLS 1.3 optimistic retry
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-74611?
CVE-2026-74611 is a critical vulnerability in Linux, published on 22 Aug 2026.
Official description
In the Linux kernel, the following vulnerability has been resolved:
tls: rx: restore msg_iter before TLS 1.3 optimistic retry
tls_decrypt_sg() advances msg->msg_iter when it maps user pages for the optimistic TLS 1.3 zero-copy path. If the decrypted record turns out not to be unpadded application data, tls_decrypt_sw() retries into a kernel skb, but leaves the iterator advanced.
The subsequent copy from the skb then writes decrypted bytes again at a later point in the caller iovecs while recvmsg() reports only the post-retry length. A TLS peer can trigger this after the receiver enables TLS_RX_EXPECT_NO_PAD.
Revert the iterator by the number of bytes consumed by the optimistic mapping before retrying without zero-copy.
Add a selftest which sends a TLS 1.3 control record with TLS_RX_EXPECT_NO_PAD enabled and verifies that recvmsg() does not overwrite later iovecs beyond the returned length.
Which versions are affected by CVE-2026-74611?
How do I fix CVE-2026-74611?
Upgrade to a fixed version.
Is CVE-2026-74611 being exploited?
There is no known exploitation of CVE-2026-74611 in the wild and no public exploit code.
Sources
Also known as AZL-97334, BELL-CVE-2026-74611, DEBIAN-CVE-2026-74611, GHSA-g4xp-j3j4-vmrq, UBUNTU-CVE-2026-74611.