Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2026-90325: blk-cgroup: skip dying blkg in blkcg_activate_policy()

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.16% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 083b58373463a6e5ee60ecb135269348f68ad7df, 1a267295b1ea6a6477963f3fda84adfecd48fcad, 3d8c3da95c75a4d312e272fc7b4076dd3ba9115c.

Low priority for now. Upgrade to Linux Linux 083b58373463a6e5ee60ecb135269348f68ad7df, 1a267295b1ea6a6477963f3fda84adfecd48fcad, 3d8c3da95c75a4d312e272fc7b4076dd3ba9115c or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: skip dying blkg in blkcg_activate_policy() When switching IO schedulers on a block device, blkcg_activate_policy() can race with concurrent blkcg deletion, leading to a use-after-free in rcu_accelerate_cbs. T1: T2: blkg_destroy kill(&blkg->refcnt) // blkg->refcnt=1->0 blkg_release // call_rcu(__blkg_release) ... blkg_free_workfn ->pd_free_fn(pd) elv_iosched_store elevator_switch ... iterate blkg list blkg_get(blkg) // blkg->refcnt=0->1 list_del_init(&blkg->q_node) blkg_put(pinned_blkg) // blkg->refcnt=1->0 blkg_release // call_rcu again rcu_accelerate_cbs // uaf Fix this by checking hlist_unhashed(&blkg->blkcg_node) before getting a reference to the blkg. This is the same check used in blkg_destroy() to detect if a blkg has already been destroyed. If the blkg is already unhashed, skip processing it since it's being destroyed.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Sep 17, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 5th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-90325

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.3affected
    • 81c1188905f88b77743d1fdeeedfc8cb7b67787d and later · before b5dae1cd0d8368b4338430ff93403df67f0b8bccaffected · git
    • bfe46d2efe46c5c952f982e2ca94fe2ec5e58e2a and later · before 083b58373463a6e5ee60ecb135269348f68ad7dfaffected · git
    • f1c006f1c6850c14040f8337753a63119bba39b9 and later · before 1a267295b1ea6a6477963f3fda84adfecd48fcadaffected · git
    • f1c006f1c6850c14040f8337753a63119bba39b9 and later · before 7337d012ca3fc3a6a2d1c8e2a19c6d97c38b410daffected · git
    • f1c006f1c6850c14040f8337753a63119bba39b9 and later · before 3d8c3da95c75a4d312e272fc7b4076dd3ba9115caffected · git
    • f1c006f1c6850c14040f8337753a63119bba39b9 and later · before d8c872901e6459339374e9eea80aa919176c2ccdaffected · git
    • f1c006f1c6850c14040f8337753a63119bba39b9 and later · before 5e9220389920f33b6a804d50c548cd0cd1b04634affected · git
    • 6.1.16 and later · before 6.1.17affected · semver
    • 6.2.3 and later · before 6.2.4affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-90323Sep 17, 2026 · ublk: validate auto buf reg before taking uring_cmd
    0Monitor
  • ← EarlierCVE-2026-90324Sep 17, 2026 · ublk: check import_ubuf() return value
    31Monitor
  • Later →CVE-2026-90326Sep 17, 2026 · blk-cgroup: fix race between policy activation and blkg destruction
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux083b58373463a6e5ee60ecb135269348f68ad7dfVendor (CNA)
Linux Linux1a267295b1ea6a6477963f3fda84adfecd48fcadVendor (CNA)
Linux Linux3d8c3da95c75a4d312e272fc7b4076dd3ba9115cVendor (CNA)
Linux Linux5e9220389920f33b6a804d50c548cd0cd1b04634Vendor (CNA)
Linux Linux6.1.17Vendor (CNA)
Linux Linux6.2.4Vendor (CNA)
Linux Linux7337d012ca3fc3a6a2d1c8e2a19c6d97c38b410dVendor (CNA)
Linux Linuxb5dae1cd0d8368b4338430ff93403df67f0b8bccVendor (CNA)
Linux Linuxd8c872901e6459339374e9eea80aa919176c2ccdVendor (CNA)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records