# CVE-2026-74557: scsi: libiscsi: Fix stale-data leak into the SCSI sense buffer

> A malicious iSCSI target can leak stale kernel memory into the SCSI sense buffer, exposing sensitive data to userspace.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-96333, BELL-CVE-2026-74557, DEBIAN-CVE-2026-74557, GHSA-x575-q9wv-7p43, UBUNTU-CVE-2026-74557

## What is CVE-2026-74557?

CVE-2026-74557 is a high-severity vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

scsi: libiscsi: Fix stale-data leak into the SCSI sense buffer

iscsi_scsi_cmd_rsp() copies the sense data of a SCSI Response from the
target-supplied data segment.  The segment carries a 2-byte sense length
followed by the sense bytes, so it must hold 2 + senselen bytes, but the
bounds check only requires datalen >= senselen:

	senselen = get_unaligned_be16(data);
	if (datalen < senselen)
		goto invalid_datalen;
	memcpy(sc->sense_buffer, data + 2,
	       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));

A target that returns a SCSI Response whose datalen equals senselen
(with senselen <= SCSI_SENSE_BUFFERSIZE) makes the memcpy() from data +
2 read up to two bytes past the received data.  Those bytes are stale
conn->data contents and end up in the command's sense buffer, which is
returned to userspace.

Account for the 2-byte sense length prefix in the check.

## Which versions are affected by CVE-2026-74557?


## How do I fix CVE-2026-74557?

Apply the vendor's patch.

## Is CVE-2026-74557 being exploited?

There is no known exploitation of CVE-2026-74557 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74557 and fix it if it is affected.

What it is: CVE-2026-74557 is a high-severity vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74557 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-2026-74557/ (Markdown: https://insights.sbomify.com/CVE-2026-74557/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74557
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74557
- OSV: https://osv.dev/vulnerability/CVE-2026-74557

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74557/
Summaries are generated and may contain mistakes; the official description above is the record.