CVE-2026-74611
tls: rx: restore msg_iter before TLS 1.3 optimistic retry
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.
INFO
Published Date :
Aug. 22, 2026, 4:16 p.m.
Last Modified :
Aug. 22, 2026, 4:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Ensure TLS decryption handles iterator advancement correctly.
- Revert iterator by consumed bytes before non-zero-copy retry.
- Apply relevant kernel patches or updates.
- Test with TLS 1.3 control records and specific flags.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-74611.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74611 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-74611
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-74611 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74611 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 22, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'ce61327ce989b63c0bd1cc7afee00e218ee696ac', 'lessThan': '68787940274ec89f41dc91b1a68ee1a16a90735f', 'versionType': 'git'}, {'status': 'affected', 'version': 'ce61327ce989b63c0bd1cc7afee00e218ee696ac', 'lessThan': '3c837266a734e2a22b24d2d567404a501d405835', 'versionType': 'git'}, {'status': 'affected', 'version': 'ce61327ce989b63c0bd1cc7afee00e218ee696ac', 'lessThan': '1c8629651cb54f7b51db8fc0b1a9944e4a4b0f5e', 'versionType': 'git'}], 'programFiles': ['net/tls/tls_sw.c', 'tools/testing/selftests/net/tls.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.45', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.9', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/tls/tls_sw.c', 'tools/testing/selftests/net/tls.c'], 'defaultStatus': 'affected'}] Added 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. Added Reference https://git.kernel.org/stable/c/1c8629651cb54f7b51db8fc0b1a9944e4a4b0f5e Added Reference https://git.kernel.org/stable/c/3c837266a734e2a22b24d2d567404a501d405835 Added Reference https://git.kernel.org/stable/c/68787940274ec89f41dc91b1a68ee1a16a90735f