Boot hang via stalled EISA IRQ parser
Published Sep 16, 2026 · Updated Sep 16, 2026
An infinite-loop flaw in affected Linux kernels allows attackers with boot-parameter control to hang PA-RISC systems during startup. The parisc EISA eisa_irq_setup() parser logs an out-of-range eisa_irq_edge entry but continues without advancing its cursor, so it reparses the same value indefinitely. Exploitation requires control of the kernel command line and prevents the kernel from completing boot.
Summary
What happened
An infinite-loop flaw in affected Linux kernels allows attackers with boot-parameter control to hang PA-RISC systems during startup. The parisc EISA eisa_irq_setup() parser logs an out-of-range eisa_irq_edge entry but continues without advancing its cursor, so it reparses the same value indefinitely. Exploitation requires control of the kernel command line and prevents the kernel from completing boot.
The record
- CVE
- CVE-2026-89964
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <5.10.270
- Affected versionversion=0 <5.15.221
- Affected versionversion=0 <6.1.188
- Affected versionversion=0 <6.12.110
- Affected versionversion=0 <6.18.51
- Affected versionversion=0 <6.6.157
- Affected versionversion=0 <7.2.5
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <16a62a3f2128b3d86fefc082d8f631becd02bff5
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <21f063e3c2b11fb9078ccdfd3b23634313ce4f0c
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3e2691eeee83a819125dba3f42c74e1b6730d5cd
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <62d88e93ef5e1e04041e347945f7d7510eba1797
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <68659b627770f3c8d8f578e8ddee78a07d5f1d0e
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8640ade22369e248f77fbdd31a9d71b338499eef
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8b585431a16cfb9d8f2955a9fa0787ce3dceb3c2
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bb10d54b74845eb4547baa1b9e908ecd32aa64e1
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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.
Weakness, pattern, technique
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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