CVE-2026-72083
CRITICAL 9.8In the Linux kernel, the following vulnerability has been resolved: scsi: target: core: Fix iSCSI ISID use-after-free in REGISTER AND MOVE core_scsi3_emulate_pro_register_and_move() maps the PERSISTENT RESERVE OUT parameter list with transport_kmap_data_sg() and parses the destination TransportID with target_parse_pr_out_transport_id(). For an iSCSI TransportID (FORMAT CODE 01b), iscsi_parse_pr_out_transport_id() returns the ISID in iport_ptr as a raw pointer into that mapped buffer. The function then unmaps the buffer with transport_kunmap_data_sg() before dereferencing iport_ptr in strcmp(), __core_scsi3_locate_pr_reg() and core_scsi3_alloc_registration(). When the parameter list spans more than one page (PARAMETER LIST LENGTH > 4096), transport_kmap_data_sg() uses vmap() and transport_kunmap_data_sg() does vunmap(), so the kernel virtual address backing iport_ptr is torn down and every subsequent dereference is a use-after-free read of the unmapped region. Keep the parameter list mapped until iport_ptr is no longer needed: drop the early transport_kunmap_data_sg() and unmap once on the success path, right before returning. The error paths already unmap through the existing "if (buf) transport_kunmap_data_sg(cmd)" at the out: label, which now runs on every post-map error exit because buf is no longer cleared early. Only reads of the mapping happen while spinlocks are held; the map and unmap calls remain outside any lock. The sibling caller core_scsi3_decode_spec_i_port() already uses the buffer before unmapping it and is left unchanged.
Severe if exploited (CVSS 9.8), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.7%chance of exploitation in 30 days · 52nd 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-2026-72083/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-2026-72083/poc.json
Weakness (CWE)
Not classified.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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 - 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
References
Technical & other
- https://git.kernel.org/stable/c/7d56f5c868d92c9d504a34a3ea450bce481c7f63
- https://git.kernel.org/stable/c/59a2a5a37dc49a641ad6bc64aee34e5a61025ffd
- https://git.kernel.org/stable/c/9f8076cc73dfa6b10155978c160587e986b22169
- https://git.kernel.org/stable/c/a040004846f1fbe687f6ec76d9ccc27b4ead42e4
- https://git.kernel.org/stable/c/05b3e37433cf2eaf8867f1c16528aa347bb212ab
- https://git.kernel.org/stable/c/cb7bdae7fba404852ade34b0c1445fbaf3e54fbb
- https://git.kernel.org/stable/c/ef2ee18fec92088c7d8877baf7674e89389ccd66
- https://git.kernel.org/stable/c/fda6a1f3c3d7047b5ce5654487649c2daa738bfc