FreeBSD Kernel Semaphore Set semop out-of-bounds

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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8.4$0-$5k2.16

Summaryinfo

A vulnerability was found in FreeBSD Kernel. It has been classified as very critical. This impacts the function semop of the component Semaphore Set. Performing a manipulation results in out-of-bounds. This vulnerability is known as CVE-2026-58098. Attacking locally is a requirement. No exploit is available. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability was found in FreeBSD Kernel (unknown version). It has been classified as very critical. This affects the function semop of the component Semaphore Set. The manipulation with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at security.freebsd.org. This vulnerability is uniquely identified as CVE-2026-58098 since 06/29/2026. The exploitability is told to be easy. Attacking locally is a requirement. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/15/2026).

Applying the patch p1/p4/p10/p14 is able to eliminate this problem.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Vendor

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.4

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: p1/p4/p10/p14

Timelineinfo

06/29/2026 CVE reserved
10/15/2026 +108 days Advisory disclosed
10/15/2026 +0 days VulDB entry created
10/15/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: security.freebsd.org
Status: Confirmed

CVE: CVE-2026-58098 (🔒)
GCVE (CVE): GCVE-0-2026-58098
GCVE (VulDB): GCVE-100-420495

Entryinfo

Created: 10/15/2026 08:49
Changes: 10/15/2026 08:49 (55)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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