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CVE-2026-98552

Microsoft — perf/core: Fix a refcount leak in attach_perf_ctx_data()

Microsoft · Not classified by connected sources

Patch Tuesday
0

EVRS 0 of 100 Informational

Monitor

Rank 2,859 of 2,960 tracked

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Why it scores 0

Evidence available: 2 of 8 signals

No strong exploitation, disclosure, or severity signal is available for this CVE yet.

  • CISA KEVDid not apply
  • RansomwareNo data
  • Vendor exploitationNo data
  • EPSSDid not apply
  • Microsoft Exploitability IndexNo data
  • Pre-patch disclosureNo data
  • KEV recencyNo data
  • CVSSNo data

The band answers “how soon”, not “how bad”. No data for: Ransomware, Vendor exploitation, Microsoft Exploitability Index, Pre-patch disclosure, KEV recency, CVSS. Why some signals show no data

Fix

No fixed version identified yet

Affected versions

Not identified by the connected sources

Remediation

NVD lists one or more references for this CVE that aren't tagged as a patch or vendor advisory. Review them directly to confirm patch availability and applicability before making a remediation decision.

Evidence

Each value with its source
MeasureValueSource
CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. Not publishedNVD and the CVE record were checked and hold no score. NVD
FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. 0.002 (9th pctl) FIRST EPSS
Actively exploitedWhether a source of record has confirmed attacks using it in the wild. Not confirmed Patch Tuesday
Public exploit moduleA module existing is not the same as active exploitation. None known Metasploit
EUVD cross-referenceENISA's record: CVSS 0.0, assigned by Linux. Listed ENISA EUVD

Description

NVD

In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix a refcount leak in attach_perf_ctx_data() The attach_perf_ctx_data() can race on global and !global cases. The global case is protected by global_ctx_data_rwsem and shares a single reference count using perf_ctx_data.global field. But when it races with !global case, it may miss to set the global field and result in a reference count leak. CPU1 CPU2 ---------------------------------------------------------------- attach_task_ctx_data(.global=1) attach_task_ctx_data(.global=0) cd1 = alloc_perf_ctx_data(); cd2 = alloc_perf_ctx_data(); // { .global = 0, .refcount = 1 }; try_cmpxchg(); // success, // task->perf_ctx_data = cd2 try_cmpxhg(); // fail; old = cd2 refcount_inc_not_zero(&old->refcount); // success // old.refcount = 2 free_perf_ctx_data(cd1); Then later detach_global_ctx_data() will see the data but it's not marked as global, so it won't call detach_task_ctx_data().