# CVE-2026-74611: tls: rx: restore msg_iter before TLS 1.3 optimistic retry


- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 22 Aug 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-97334, BELL-CVE-2026-74611, DEBIAN-CVE-2026-74611, GHSA-g4xp-j3j4-vmrq, UBUNTU-CVE-2026-74611

## 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74611 and fix it if it is affected.

What it is: CVE-2026-74611 is a critical vulnerability in Linux, published on 22 Aug 2026. 
Exploitation: There is no known exploitation of CVE-2026-74611 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74611/ (Markdown: https://insights.sbomify.com/CVE-2026-74611/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74611
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74611
- OSV: https://osv.dev/vulnerability/CVE-2026-74611

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74611/
Summaries are generated and may contain mistakes; the official description above is the record.