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NVD / CVE Program· CNA Linux

CVE-2025-68823: ublk: fix deadlock when reading partition table

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.13% (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 0460e09a614291f06c008443f47393c37b7358e7, 27bb79b7717b2fbb111a1c13548b2786ee712dca, 64c0b7e2293757e8320f13434cd809f1c9257a62.

Low priority for now. Upgrade to Linux Linux 0460e09a614291f06c008443f47393c37b7358e7, 27bb79b7717b2fbb111a1c13548b2786ee712dca, 64c0b7e2293757e8320f13434cd809f1c9257a62 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: ublk: fix deadlock when reading partition table When one process(such as udev) opens ublk block device (e.g., to read the partition table via bdev_open()), a deadlock[1] can occur: 1. bdev_open() grabs disk->open_mutex 2. The process issues read I/O to ublk backend to read partition table 3. In __ublk_complete_rq(), blk_update_request() or blk_mq_end_request() runs bio->bi_end_io() callbacks 4. If this triggers fput() on file descriptor of ublk block device, the work may be deferred to current task's task work (see fput() implementation) 5. This eventually calls blkdev_release() from the same context 6. blkdev_release() tries to grab disk->open_mutex again 7. Deadlock: same task waiting for a mutex it already holds The fix is to run blk_update_request() and blk_mq_end_request() with bottom halves disabled. This forces blkdev_release() to run in kernel work-queue context instead of current task work context, and allows ublk server to make forward progress, and avoids the deadlock. [axboe: rewrite comment in ublk]

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Jan 13, 2026
Updated
Jun 17, 2026
EPSS
0.1% · 2th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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

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When you'll hear from us

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  • when exploit code appears or is weaponized
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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.

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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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.0 and later · before 6.6.124
  • linux linux kernel6.7 and later · before 6.12.70
  • linux linux kernel6.13 and later · before 6.18.3
  • linux linux kernel6.19

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

    • 6.0affected
    • 71f28f3136aff5890cd56de78abc673f8393cad9 and later · before 27bb79b7717b2fbb111a1c13548b2786ee712dcaaffected · git
    • 71f28f3136aff5890cd56de78abc673f8393cad9 and later · before 64c0b7e2293757e8320f13434cd809f1c9257a62affected · git
    • 71f28f3136aff5890cd56de78abc673f8393cad9 and later · before 9bcc47343ee0ef346aa7b2b460c8ff56bd882fe7affected · git
    • 71f28f3136aff5890cd56de78abc673f8393cad9 and later · before 0460e09a614291f06c008443f47393c37b7358e7affected · git
    • 71f28f3136aff5890cd56de78abc673f8393cad9 and later · before c258f5c4502c9667bccf5d76fa731ab9c96687c1affected · git
    • before 6.0not affected · semver
    • 6.1.175 and later · up to and including 6.1.*not affected · semver
    • 6.6.124 and later · up to and including 6.6.*not affected · semver
    • 6.12.70 and later · up to and including 6.12.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.73-16.12.73-1
Debian:14linuxbefore 6.18.3-16.18.3-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-67707Dec 31, 2025 · Unvalidated File Upload vulnerability in ArcGIS Server.
    22Monitor
  • ← EarlierCVE-2025-68817Jan 13, 2026 · ksmbd: fix use-after-free in ksmbd_tree_connect_put under concurrency
    31Monitor
  • Later →CVE-2025-71071Jan 13, 2026 · iommu/mediatek: fix use-after-free on probe deferral
    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 Linux0460e09a614291f06c008443f47393c37b7358e7Vendor (CNA)
Linux Linux27bb79b7717b2fbb111a1c13548b2786ee712dcaVendor (CNA)
Linux Linux64c0b7e2293757e8320f13434cd809f1c9257a62Vendor (CNA)
Linux Linux9bcc47343ee0ef346aa7b2b460c8ff56bd882fe7Vendor (CNA)
Linux Linuxc258f5c4502c9667bccf5d76fa731ab9c96687c1Vendor (CNA)
debian:linux6.1.176-1 · 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.

No history yet (it accumulates with the daily EPSS job).

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

Weakness class (CWE)

CWE-667 · Improper Locking

CVSS vector

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

nvd-primary

Attack context

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

Change log

  1. Fix✗ → ✓

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

References

Show all references (4 more)

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

All records