- 9.3CriticalCVSS base score
- 0.18%Exploitation in 30 daysEPSS · top 92% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: scsi: xen: scsiback: Free unsubmitted command instead of double-putting it scsiback_get_pend_req() obtains a command tag and returns a vscsibk_pend whose embedded se_cmd has only been memset to 0, so its cmd_kref is 0; the se_cmd is initialised (kref_init() via target_init_cmd()) only later, in scsiback_cmd_exec(), on the successful VSCSIIF_ACT_SCSI_CDB path. The two error paths in scsiback_do_cmd_fn() taken before the command is submitted -- a failed scsiback_gnttab_data_map() and an unknown ring_req.act -- call transport_generic_free_cmd(&pending_req->se_cmd, 0), which kref_put()s a refcount of 0. That underflows it ("refcount_t: underflow; use-after-free") and, as the release function is not run, leaks the command tag. Impact: a pvSCSI guest can leak every command tag of a LUN's session, stopping the LUN, by submitting requests with a bad grant reference or an unknown request type; under panic_on_warn the refcount underflow panics the host. Add a helper that just returns the tag with target_free_tag() and sends the error response. It frees the tag while the v2p reference still pins the session, and snapshots the response fields beforehand because freeing the tag can let another ring reuse the pending_req slot.
Timeline
ID reserved
By Linux
- 6 days later
· 6 days later
Published
- 2 months later
· 2 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.3 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | Critical9.3 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.18% · top 92% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.3.
Affected products
- affected 2dbcdf33dbf61f44b29adb52338282c3d7840d0e – < 9c0f6894982b1f13bda220707497b25ac9c95bdb
- affected 2dbcdf33dbf61f44b29adb52338282c3d7840d0e – < a13b789497a7fdd27d4d63f5c69d23db706ef0fe
- affected 2dbcdf33dbf61f44b29adb52338282c3d7840d0e – < fa588f28401102652068c4cc75e135507f4b5106
- affected 2dbcdf33dbf61f44b29adb52338282c3d7840d0e – < fcd64d4d97af5d9736f31040f8ed8cd4c17e4c45
- affected 2dbcdf33dbf61f44b29adb52338282c3d7840d0e – < f1516c56ac540da1769f264c3cfefe4499548a5d
- affected 2dbcdf33dbf61f44b29adb52338282c3d7840d0e – < 1e97c404e44991fb087c38ccd7414f2d326f9b74
- affected 2dbcdf33dbf61f44b29adb52338282c3d7840d0e – < ca978f8a93d4d36841839bf2847d29b88c2591d6
- affected 4.6
- unaffected < 4.6
- unaffected 5.15.212 – ≤ 5.15.*
- unaffected 6.1.178 – ≤ 6.1.*
- unaffected 6.6.145 – ≤ 6.6.*
- unaffected 6.12.97 – ≤ 6.12.*
- unaffected 6.18.40 – ≤ 6.18.*
- unaffected 7.1.5 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References7
- https://git.kernel.org/stable/c/9c0f6894982b1f13bda220707497b25ac9c95bdb (opens in a new tab)
- https://git.kernel.org/stable/c/a13b789497a7fdd27d4d63f5c69d23db706ef0fe (opens in a new tab)
- https://git.kernel.org/stable/c/fa588f28401102652068c4cc75e135507f4b5106 (opens in a new tab)
- https://git.kernel.org/stable/c/fcd64d4d97af5d9736f31040f8ed8cd4c17e4c45 (opens in a new tab)
- https://git.kernel.org/stable/c/f1516c56ac540da1769f264c3cfefe4499548a5d (opens in a new tab)
- https://git.kernel.org/stable/c/1e97c404e44991fb087c38ccd7414f2d326f9b74 (opens in a new tab)
- https://git.kernel.org/stable/c/ca978f8a93d4d36841839bf2847d29b88c2591d6 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-59043 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-72085)Record last updated .