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NVD / CVE Program· CNA Linux

CVE-2023-53501: iommu/amd/iommu_v2: Fix pasid_state refcount dec hit 0 warning on pasid unbind

Noroxi assessment

Priority: Monitor (action score 18/100)

  • 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: 0.15% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Linux Linux 13ed255248dfbbb7f23f9170c7a537fb9ca22c73, 534103bcd52ca9c1fecbc70e717b4a538dc4ded8, 98d86bf32187db27946ca817c2467a5f2f7aa02f.

Low priority for now. Upgrade to Linux Linux 13ed255248dfbbb7f23f9170c7a537fb9ca22c73, 534103bcd52ca9c1fecbc70e717b4a538dc4ded8, 98d86bf32187db27946ca817c2467a5f2f7aa02f 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: iommu/amd/iommu_v2: Fix pasid_state refcount dec hit 0 warning on pasid unbind When unbinding pasid - a race condition exists vs outstanding page faults. To prevent this, the pasid_state object contains a refcount. * set to 1 on pasid bind * incremented on each ppr notification start * decremented on each ppr notification done * decremented on pasid unbind Since refcount_dec assumes that refcount will never reach 0: the current implementation causes the following to be invoked on pasid unbind: REFCOUNT_WARN("decrement hit 0; leaking memory") Fix this issue by changing refcount_dec to refcount_dec_and_test to explicitly handle refcount=1.

MediumCVSS 4.7 · v3.1—No exploit Fix available
Published
Oct 1, 2025
Updated
Jun 17, 2026
EPSS
0.1% · 4th percentile
CWE
—

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
18 / 40 · 4.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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.

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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

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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 kernel5.15 and later · before 5.15.132
  • linux linux kernel5.16 and later · before 6.1.53
  • linux linux kernel6.2 and later · before 6.4.16
  • linux linux kernel6.5 and later · before 6.5.3

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

    • 5.15affected
    • 8bc54824da4e8fcf0ed679cf09ac32f23d83254a and later · before a50d60b8f2aff46dd7c7edb4a5835cdc4d432c22affected · git
    • 8bc54824da4e8fcf0ed679cf09ac32f23d83254a and later · before 13ed255248dfbbb7f23f9170c7a537fb9ca22c73affected · git
    • 8bc54824da4e8fcf0ed679cf09ac32f23d83254a and later · before 9ccc51be3126b25cfe9351dbffde946c925cc28aaffected · git
    • 8bc54824da4e8fcf0ed679cf09ac32f23d83254a and later · before 98d86bf32187db27946ca817c2467a5f2f7aa02faffected · git
    • 8bc54824da4e8fcf0ed679cf09ac32f23d83254a and later · before 534103bcd52ca9c1fecbc70e717b4a538dc4ded8affected · git
    • before 5.15not affected · semver
    • 5.15.132 and later · up to and including 5.15.*not affected · semver
    • 6.1.53 and later · up to and including 6.1.*not affected · semver
    • 6.4.16 and later · up to and including 6.4.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.55-16.1.55-1
Debian:13linuxbefore 6.5.3-16.5.3-1

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-2023-53497Oct 1, 2025 · media: vsp1: Replace vb2_is_streaming() with vb2_start_streaming_called()
    22Monitor
  • ← EarlierCVE-2023-53498Oct 1, 2025 · drm/amd/display: Fix potential null dereference
    22Monitor
  • Later →CVE-2023-53503Oct 1, 2025 · ext4: allow ext4_get_group_info() to fail
    22Monitor

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 Linux13ed255248dfbbb7f23f9170c7a537fb9ca22c73Vendor (CNA)
Linux Linux534103bcd52ca9c1fecbc70e717b4a538dc4ded8Vendor (CNA)
Linux Linux98d86bf32187db27946ca817c2467a5f2f7aa02fVendor (CNA)
Linux Linux9ccc51be3126b25cfe9351dbffde946c925cc28aVendor (CNA)
Linux Linuxa50d60b8f2aff46dd7c7edb4a5835cdc4d432c22Vendor (CNA)
debian:linux6.1.55-1 · 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.

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.
  • Special conditions such as timing or configuration are required.

If successful

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

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:H/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.

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 (4 more)

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

All records