CVE-2026-52989
CRITICAL 9.8In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers Currently, when nvmet_tcp_build_pdu_iovec() detects an out-of-bounds PDU length or offset, it triggers nvmet_tcp_fatal_error(cmd->queue) and returns early. However, because the function returns void, the callers are entirely unaware that a fatal error has occurred and that the cmd->recv_msg.msg_iter was left uninitialized. Callers such as nvmet_tcp_handle_h2c_data_pdu() proceed to blindly overwrite the queue state with queue->rcv_state = NVMET_TCP_RECV_DATA Consequently, the socket receiving loop may attempt to read incoming network data into the uninitialized iterator. Fix this by shifting the error handling responsibility to the callers.
Severe if exploited (CVSS 9.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 27th percentile
Impact if exploited
9.8CVSS 3.1 · CRITICAL
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-52989/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-52989/poc.json
Affected
Products Linux Red Hat Enterprise Linux 10 Red Hat Enterprise Linux 6 Red Hat Enterprise Linux 7 Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 9 Linux Kernel
Weakness (CWE)
- CWE-390: Detection of Error Condition Without Action
- CWE-908: Use of Uninitialized Resource
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Linux | Linux Kernel | ≥ 5.10.250 and < 5.11 |
| Linux | Linux Kernel | ≥ 5.15.200 and < 5.16 |
| Linux | Linux Kernel | ≥ 6.1.163 and < 6.1.175 |
| Linux | Linux Kernel | ≥ 6.6.124 and < 6.6.141 |
| Linux | Linux Kernel | ≥ 6.12.70 and < 6.12.91 |
| Linux | Linux Kernel | ≥ 6.18.10 and < 6.18.33 |
| Linux | Linux Kernel | ≥ 6.19.1 and < 7.0.10 |
| Linux | Linux Kernel | 6.19 |
| Linux | Linux Kernel | 7.1 |
All CVSS metrics
- CRITICAL 9.8 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - HIGH 7 v3.1 · ADP Primary
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - CRITICAL 9.8 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - HIGH 7 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
References
Patches & mitigations
- https://git.kernel.org/stable/c/3df42a854686fa06484e37ac1a3931c8e3e3453c
- https://git.kernel.org/stable/c/d7c8f95f599b3b38a717d2e771c3f8c174f657c3
- https://git.kernel.org/stable/c/f9204a2b78dd18374d3bcf9bf93d9021ce22de1b
- https://git.kernel.org/stable/c/c2a11441538bdbbc5aa003f190995eba93a89b88
- https://git.kernel.org/stable/c/046fa5c72d15cd8e2d592e275697ea399d8f76b0
- https://git.kernel.org/stable/c/ea8e356acb165cb1fd75537a52e1f66e5e76c538