CVE-2026-98551: Linux kernel · perf/core: Fill branch entries with a single assignment
Affects Linux kernelSource CVE Database V5
Not known to be exploited : upgrade to c7de8521947a521b766979ff5c09f66fe905a5bd or 24b620729e53d978b3e425f55bc66efd3bab1f59 when convenient.
Data as of 26 Oct 2026, 13:47 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in c7de8521947a521b766979ff5c09f66fe905a5bd, 24b620729e53d978b3e425f55bc66efd3bab1f59
Exploitation evidence
Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade Linux kernel to c7de8521947a521b766979ff5c09f66fe905a5bd or 24b620729e53d978b3e425f55bc66efd3bab1f59.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been applied in the Linux kernel source (commits c7de8521947a521b766979ff5c09f66fe905a5bd and 24b620729e53d978b3e425f55bc66efd3bab1f59). Users and administrators should update to the fixed Linux kernel versions to remediate this vulnerability. No additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel's perf subsystem related to branch entry handling was fixed. The issue involved uninitialized or stale data in certain fields of the perf_branch_entry struct on arm64 architectures due to incomplete clearing of bitfields. This could cause userspace to receive unintended data from the kernel's performance monitoring. The flaw was addressed by assigning the entire branch entry at once, ensuring all fields are properly initialized. The fix removes the outdated clearing function and prevents use of uninitialized data.