CVE-2026-90188 — null_blk: free global tag_set on init error path
In the Linux kernel, the following vulnerability has been resolved: null_blk: free global tag_set on init error path If shared_tags is enabled, null_setup_tagset() allocates the global tag_set via null_init_global_tag_set(). If device creation later fails, err_dev destroys the default devices and calls unregister_blkdev(), but never frees the global tag_set. Since module init failed, null_exit() is never invoked, so the global tag_set's tags and maps are permanently leaked. Free the global tag_set in err_dev, matching null_exit() which does if (tag_set.ops) blk_mq_free_tag_set(&tag_set).
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ 82f402fefa50f1675bf918bcd009981bd6b30ac8 and < 0b2faa330184340d9418ad2c627c2ae881772e33≥ 82f402fefa50f1675bf918bcd009981bd6b30ac8 and < 665c94554ff0d5d88caae7f40c16c8e0a3369eda≥ 82f402fefa50f1675bf918bcd009981bd6b30ac8 and < 2882e1450fa4597811a951196e07553ea134eb31≥ 82f402fefa50f1675bf918bcd009981bd6b30ac8 and < 2b59484ac1e64dd78dbe8c6140891c6308085a75≥ 82f402fefa50f1675bf918bcd009981bd6b30ac8 and < 081cf37e8a0e00cd91d6df53172c9d928790a798≥ 82f402fefa50f1675bf918bcd009981bd6b30ac8 and < 5a1c5ff3a49ba93a1fd0b70537e7a0164071760dversion 4.13 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 18, 2026 · 3 reading(s) · max 0.21%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 19, 2026 – Oct 19, 2026
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
8 on the record
- git.kernel.org/stable/c/665c94554ff0d5d88caae7f40c16c8e0a3369eda
- github.com/advisories/GHSA-jmg2-qcvp-f7gg
- git.kernel.org/stable/c/2882e1450fa4597811a951196e07553ea134eb31
- nvd.nist.gov/vuln/detail/CVE-2026-90188
- git.kernel.org/stable/c/0b2faa330184340d9418ad2c627c2ae881772e33
- git.kernel.org/stable/c/081cf37e8a0e00cd91d6df53172c9d928790a798
- git.kernel.org/stable/c/2b59484ac1e64dd78dbe8c6140891c6308085a75
- git.kernel.org/stable/c/5a1c5ff3a49ba93a1fd0b70537e7a0164071760d
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-98868 dm-pcache: reject a kset that overruns its segment 1d
- Unknown CVE-2026-98866 sched/cache: Introduce task_struct->sched_cache_grp to fix UAF 1d
- Unknown CVE-2026-98867 dm-pcache: bound the logical key offset from persistent memory 1d
- Unknown CVE-2026-98865 sched_ext: Don't run ops.dequeue() with a DSQ lock held 1d
- Unknown CVE-2026-98864 sched_ext: Wait for SCX_OPSS_DISPATCHING before reenqueueing a task 1d
- Unknown CVE-2026-98863 KVM: x86: Re-pend GET_NESTED_STATE_PAGES if getting said pages fails 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-90188 is "null_blk: free global tag_set on init error path", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.21% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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