Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2026-52933: io_uring/poll: fix signed comparison in io_poll_get_ownership()

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: 0.14% (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 326941b22806cbf2df1fbfe902b7908b368cce42, 5.16, 6.1; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.143.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 326941b22806cbf2df1fbfe902b7908b368cce42, 5.16, 6.1; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.143.1-1 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: io_uring/poll: fix signed comparison in io_poll_get_ownership() io_poll_get_ownership() uses a signed comparison to check whether poll_refs has reached the threshold for the slowpath: if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS)) atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG (BIT(31)) is set in poll_refs, the value becomes negative in signed arithmetic, so the >= 128 comparison always evaluates to false and the slowpath is never taken. Fix this by casting the atomic_read() result to unsigned int before the comparison, so that the cancel flag is treated as a large positive value and correctly triggers the slowpath.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Jun 24, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 3th percentile

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%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

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-2026-52933

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.

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 kernel5.15.82 and later · before 5.16
  • linux linux kernel6.0.11 and later · before 6.1
  • linux linux kernel6.1.1 and later · before 6.1.175
  • linux linux kernel6.2 and later · before 6.6.140
  • linux linux kernel6.7 and later · before 6.12.86
  • linux linux kernel6.13 and later · before 6.18.27
  • linux linux kernel6.19 and later · before 7.0.4
  • linux linux kernel6.1

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

    • 4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048, bc4e6ee16778149811333a969a7a893d4cc110c5, 6.1affected
    • a26a35e9019fd70bf3cf647dcfdae87abc7bacea and later · before 81bf96b0abbfa4cd47ea32e12596aed3855fb2f3affected · git
    • a26a35e9019fd70bf3cf647dcfdae87abc7bacea and later · before cf522703d4f194991615763697ae25a3f9539763affected · git
    • a26a35e9019fd70bf3cf647dcfdae87abc7bacea and later · before fc47043f3d9af3efa407665b47f8378ec691ba18affected · git
    • a26a35e9019fd70bf3cf647dcfdae87abc7bacea and later · before ea0697129807d718037f618221037aa0660ee3c5affected · git
    • a26a35e9019fd70bf3cf647dcfdae87abc7bacea and later · before c6d191164dc81838d8dbf452a6000f68c558d1aeaffected · git
    • a26a35e9019fd70bf3cf647dcfdae87abc7bacea and later · before 326941b22806cbf2df1fbfe902b7908b368cce42affected · git
    • 5.15.82 and later · before 5.16affected · semver
    • 6.0.11 and later · before 6.1affected · semver
    • before 6.1not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:9kernelbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64kbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debugbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-develbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-devel-matchedbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-modulesbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-modules-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-debug-modules-extrabefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-develbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-devel-matchedbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-modulesbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-modules-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-64k-modules-extrabefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-abi-stablelistsbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-cross-headersbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debugbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debug-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debug-develbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debug-devel-matchedbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debug-modulesbefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8
AlmaLinux:9kernel-debug-modules-corebefore 5.14.0-687.45.1.el9_85.14.0-687.45.1.el9_8

+96

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-2026-52930Jun 24, 2026 · ipc/shm: serialize orphan cleanup with shm_nattch updates
    22Monitor
  • ← EarlierCVE-2026-52931Jun 24, 2026 · batman-adv: tp_meter: avoid use of uninit sender vars
    39Monitor
  • Later →CVE-2026-52935Jun 24, 2026 · xfrm: espintcp: do not reuse an in-progress partial send
    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 Linux326941b22806cbf2df1fbfe902b7908b368cce42Vendor (CNA)
Linux Linux5.16Vendor (CNA)
Linux Linux6.1Vendor (CNA)
Linux Linux81bf96b0abbfa4cd47ea32e12596aed3855fb2f3Vendor (CNA)
Linux Linuxc6d191164dc81838d8dbf452a6000f68c558d1aeVendor (CNA)
Linux Linuxcf522703d4f194991615763697ae25a3f9539763Vendor (CNA)
Linux Linuxea0697129807d718037f618221037aa0660ee3c5Vendor (CNA)
Linux Linuxfc47043f3d9af3efa407665b47f8378ec691ba18Vendor (CNA)
azl3 kernel 6.6.139.1-1 on Azure Linux 3.06.6.143.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:kernel5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel-matched5.14.0-687.45.1.el9_8 · AlmaLinux:9Package registry (OSV)
debian:linux6.1.176-1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)

+5

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.

  • CVE-2026-3144863 days apartext4: avoid infinite loops caused by residual data
    37Monitor
  • CVE-2026-6388925 days apartscsi: scsi_transport_fc: Widen FPIN pname walker counter to u32
    32Monitor
  • CVE-2026-6396825 days apartipv6: fix possible infinite loop in fib6_select_path()
    30Monitor
  • CVE-2026-6414825 days apartpds_core: fix error handling in pdsc_devcmd_wait
    30Monitor
  • CVE-2026-4605228 days apartceph: only d_add() negative dentries when they are unhashed
    30Monitor
  • CVE-2026-3155261 days apartwifi: wlcore: Return -ENOMEM instead of -EAGAIN if there is not enough headroom
    30Monitor

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

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)

CWE-835 · Loop with Unreachable Exit Condition ('Infinite Loop')

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. SSVC exploitation— → none
  2. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records