CVE-2026-58098
Full vulnerability record from the local CVENow database.
Description
When semop(2) blocks waiting for a semaphore condition, it releases the per-set lock and sleeps. Upon waking, it checks the sequence number embedded in the semaphore set's IPC identifier to detect whether the set was removed while the caller was asleep. This sequence number is only 15 bits wide. If enough semaphore sets are created and destroyed in the same table slot while a caller is blocked, the counter wraps around, and semop(2) may falsely conclude that the original set still exists. The subsequent access to a semaphore within the set may then be out of bounds. An unprivileged local user can trigger an out-of-bounds access on kernel heap memory, potentially leading to privilege escalation.
Severity
HIGH
CVSS score
8.4
(v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-10-15 07:18:02.250000
Last modified
2026-10-19 21:05:21.253000
View original CVE JSON
{
"id": "CVE-2026-58098",
"sourceIdentifier": "[email protected]",
"published": "2026-10-15T07:18:02.250",
"lastModified": "2026-10-19T21:05:21.253",
"vulnStatus": "Analyzed",
"cveTags": [],
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{
"lang": "en",
"value": "When semop(2) blocks waiting for a semaphore condition, it releases the per-set lock and sleeps. Upon waking, it checks the sequence number embedded in the semaphore set's IPC identifier to detect whether the set was removed while the caller was asleep. This sequence number is only 15 bits wide. If enough semaphore sets are created and destroyed in the same table slot while a caller is blocked, the counter wraps around, and semop(2) may falsely conclude that the original set still exists. The subsequent access to a semaphore within the set may then be out of bounds.\n\nAn unprivileged local user can trigger an out-of-bounds access on kernel heap memory, potentially leading to privilege escalation."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "FreeBSD",
"product": "FreeBSD",
"defaultStatus": "unknown",
"modules": [
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"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
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"description": [
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"references": [
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"url": "https://security.freebsd.org/advisories/FreeBSD-SA-26:64.sysvsem.asc",
"source": "[email protected]",
"tags": [
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]
}
]
}