Out-of-bounds read in Linux kernel libiscsi via negative task index
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 7 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
The Linux kernel libiscsi code is affected from 2.6.33 before the fixed versions, in the lookups that use the task index from parse_pdu_itt. Both lookups check only the upper bound, so a negative index taken from a PDU reads memory before the session command array. The be2iscsi driver can produce such an index from an unsolicited NOP-In, so a remote attacker without authentication can cause high impact to confidentiality, integrity and availability.
Written with Claude Haiku 5.5 from the sources below · 2026-11-02
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi: Reject a negative task index from parse_pdu_itt A transport that implements parse_pdu_itt hands libiscsi an index taken from the PDU, and both lookups bound it from above only: if (i >= session->cmds_max) i and cmds_max are both int, so a negative index passes and session->cmds[i] is read from before the array. be2iscsi produces one. beiscsi_parse_pdu() assigns the raw tag, *index = (int)itt; and beiscsi_complete_pdu() forwards an unsolicited NOP-In from the hardware async ring without replacing its ITT, so the value is the target's. It also reports the session's own age rather than the one in the tag, which leaves the age comparison in iscsi_verify_itt() with nothing to reject. Bound the index from below in both lookups.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 2.6.33 and later | 5.10.273, 5.15.224, 6.1.191, 6.6.161, 6.12.115, 6.18.59, 7.2.13, 7.3 | Patch available | CNA |
- Linux VendorLinux Affected 2.6.33 and later Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.161, 6.12.115, 6.18.59, 7.2.13, 7.3 Patch available CNA
Remediation
Fixed Linux kernel releases are 5.10.273, 5.15.224, 6.1.191, 6.6.161, 6.12.115, 6.18.59, 7.2.13 and 7.3. Red Hat Enterprise Linux 6 has the plan no fix planned, and Red Hat Enterprise Linux 7, 8, 9, 10 and OpenShift Container Platform 4 and 5 have the plan none available.
Written with Claude Haiku 5.5 from the sources below · 2026-11-02
- Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.161, 6.12.115, 6.18.59, 7.2.13, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-28 Threatist record created from CVE-2026-99154
- 2026-10-28 Alias added: GHSA-x6ph-vjqm-9q4f
- 2026-10-30 Fix available: Linux/Linux@0eb06ebbbecb122f0df9a1f7f623f5255be741ed, Linux/Linux@24bd9ba431b2daa263f3551bc2f09f6b4487f5ae, Linux/[email protected] +7 · CNA
- 2026-10-30 5 new references · CNA
- 2026-10-31 CVSS score added · CNA
- 2026-10-31 Priority changed: LOW → MEDIUM
- 2026-11-01 Affected versions changed · Red Hat
- 2026-11-01 CVSS score added · Red Hat
- 2026-11-02 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/24bd9ba431b2daa263f3551bc2f09f6b4487f5ae
- https://git.kernel.org/stable/c/f8fabe1fe044f86abc42194b8f86dfd70212115f
- https://git.kernel.org/stable/c/e896a97f336c5edfc13066b57ed431cb3f64e68c
- https://git.kernel.org/stable/c/6200fb2de579f268742a77b0f3d823cb0a8b1947
- https://git.kernel.org/stable/c/0eb06ebbbecb122f0df9a1f7f623f5255be741ed
- https://git.kernel.org/stable/c/6cadfa6f1f5896632d4223d3b7addb2a29fea74e
- https://git.kernel.org/stable/c/35b60549a956237488c89a2d85352e026e7d55b7
- https://git.kernel.org/stable/c/8ee2a09a1dbb257c9e828ad2497f8e4832dfb142
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Sources
- CVE-2026-99154 · CVE Program
- CVE-2026-99154 · NVD
- FIRST EPSS
- GHSA-x6ph-vjqm-9q4f · GitHub Advisory Database · CC BY 4.0
- CVE-2026-99154 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences