CVE-2026-17523

Root escalation via CAN BCM tasklet race

Published Jul 27, 2026 · Updated Jul 27, 2026

Expired pointer dereference in the Red Hat Enterprise Linux 8 CAN BCM kernel module allows local users to execute kernel code and gain root. The net/can/bcm.c timer handlers schedule tasklets with a bcm_op pointer while teardown can cancel timers and free the operation, leaving a callback to dereference expired state. An unprivileged local account can trigger the flaw even without unprivileged user namespaces or the kernel-modules-extra package, resulting in full kernel-level control.

CVSS severity7.8
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Expired pointer dereference in the Red Hat Enterprise Linux 8 CAN BCM kernel module allows local users to execute kernel code and gain root. The net/can/bcm.c timer handlers schedule tasklets with a bcm_op pointer while teardown can cancel timers and free the operation, leaving a callback to dereference expired state. An unprivileged local account can trigger the flaw even without unprivileged user namespaces or the kernel-modules-extra package, resulting in full kernel-level control.

The record

CVE
CVE-2026-17523
Published
Jul 27, 2026
Updated
Jul 27, 2026
Vendor
389 Directory Server
Product
Red Hat Enterprise Linux 8
Classifications
CWE-825, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

389 Directory Server · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.

Published CVSS scores

7.8Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-825Expired Pointer Dereference
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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