Evidence-led vulnerability intelligence · 2026-05-21 18:46 IST

CVE-2026-43499

In the Linux kernel, the following vulnerability has been resolved: rtmutex: Use waiter::task instead of current in remove_waiter() remove_waiter() is used by the slowlock paths, but it is also used for proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from futex_requeue(). In the latter case waiter::task is not current, but remove_waiter() operates on current for the dequeue operation. That results in several problems: 1) the rbtree dequeue happens without waiter::task::pi_lock being held 2) the waiter task's pi_blocked_on state is not cleared, which leaves a dangling pointer primed for UAF around. 3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter task Use waiter::task instead of current in all related operations in remove_waiter() to cure those problems. [ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the changelog ]

HIGH · 7.8Linux

Executive briefing

The source record describes: In the Linux kernel, the following vulnerability has been resolved: rtmutex: Use waiter::task instead of current in remove_waiter() remove_waiter() is used by the slowlock paths, but it is also used for proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from futex_requeue(). In the latter case waiter::task is not current, but remove_waiter() operates on current for the dequeue operation. That results in several problems: 1) the rbtree dequeue happens without waiter::task::pi_lock being held 2) the waiter task's pi_blocked_on state is not cleared, which leaves a dangling pointer primed for UAF around. 3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter task Use waiter::task instead of current in all related operations in remove_waiter() to cure those problems. [ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the changelog ] The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.

Assessment: Potential exposure only — validate the installed product, exact version, configuration and vendor applicability before treating an asset as confirmed vulnerable.

Evidence confidence: Moderate Evidence-derived, not an exploitability verdict

Severity & attack characteristics

7.8 / 10 · 3.1

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

Attack vectorL
Attack complexityL
Privileges requiredL
User interactionN
ScopeU
Confidentiality impactH
Integrity impactH
Availability impactH

Technical explanation & impact

The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.

Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.

Weakness classification

CWE-416

Affected products and versions

Products below are parsed from NVD vulnerable CPE configuration entries. Version boundaries are shown as published; verify applicability with the vendor.

VendorProductVersion evidence
linuxlinux_kernelfrom (inclusive) 6.19; before 7.0.4

Remediation & validation

  1. Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
  2. Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
  3. Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
  4. Validate the remediation with a version check and vulnerability rescan, then retain change evidence.

No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.

Vendor advisories, patches & exploit references

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