How severe is CVE-2023-43766?

CVE-2023-43766 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-43766 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-43766?

CVE-2023-43766 primarily affects F-secure Linux Protection. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-43766?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2023-43766 published?

CVE-2023-43766 was published on 2023-09-22 and last updated on 2026-06-17.

CVE-2023-43766

CVE-2023-43766 is a high-severity vulnerability in F-secure Linux Protection with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-269.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-269
Affected product: F-secure Linux Protection
Published: 2023-09-22
Last modified: 2026-06-17

Description

Certain WithSecure products allow Local privilege escalation via the lhz archive unpack handler. This affects WithSecure Client Security 15, WithSecure Server Security 15, WithSecure Email and Server Security 15, WithSecure Elements Endpoint Protection 17 and later, WithSecure Client Security for Mac 15, WithSecure Elements Endpoint Protection for Mac 17 and later, Linux Security 64 12.0 , Linux Protection 12.0, and WithSecure Atlant (formerly F-Secure Atlant) 1.0.35-1.

Frequently asked questions

What is CVE-2023-43766?: Certain WithSecure products allow Local privilege escalation via the lhz archive unpack handler. This affects WithSecure Client Security 15, WithSecure Server Security 15, WithSecure Email and Server Security 15, WithSecure Elements Endpoint Protection 17 and later, WithSecure Client Security for Mac 15, WithSecure Elements Endpoint Protection for Mac 17 and later, Linux Security 64 12.0 , Linux Protection 12.0, and WithSecure Atlant (formerly F-Secure Atlant) 1.0.35-1.
How severe is CVE-2023-43766?: CVE-2023-43766 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-43766 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-43766?: CVE-2023-43766 primarily affects F-secure Linux Protection. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-43766?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-43766 published?: CVE-2023-43766 was published on 2023-09-22 and last updated on 2026-06-17.

References

Affected products (7)

cpe:2.3:a:f-secure:linux_protection:12.0:*:*:*:*:*:*:*
cpe:2.3:a:f-secure:linux_security_64:12.0:*:*:*:*:*:*:*
cpe:2.3:a:f-secure:atlant:1.0.35-1:*:*:*:*:*:*:*
cpe:2.3:a:f-secure:client_security:15.00:*:*:*:*:*:*:*
cpe:2.3:a:f-secure:elements_endpoint_protection:*:*:*:*:*:*:*:*
cpe:2.3:a:f-secure:email_and_server_security:15.00:*:*:*:*:*:*:*
cpe:2.3:a:f-secure:server_security:15.00:*:*:*:*:*:*:*

More vulnerabilities in F-secure Linux Protection

CVE-2023-49322 — High (CVSS 7.5): Certain WithSecure products allow a Denial of Service because there is an unpack handler crash that can lead to a…
CVE-2023-43767 — High (CVSS 7.5): Certain WithSecure products allow Denial of Service via the aepack archive unpack handler. This affects WithSecure…
CVE-2023-43765 — High (CVSS 7.5): Certain WithSecure products allow Denial of Service in the aeelf component. This affects WithSecure Client Security 15,…
CVE-2023-43761 — High (CVSS 7.5): Certain WithSecure products allow Denial of Service (infinite loop). This affects WithSecure Client Security 15,…
CVE-2023-43760 — High (CVSS 7.5): Certain WithSecure products allow Denial of Service via a fuzzed PE32 file. This affects WithSecure Client Security 15,…
CVE-2023-49321 — Medium (CVSS 5.3): Certain WithSecure products allow a Denial of Service because scanning a crafted file takes a long time, and causes the…

All CVEs affecting F-secure Linux Protection →

Other CWE-269 (Improper Privilege Management) vulnerabilities

CVE-2026-31852 — Critical (CVSS 10.0): Jellyfin is an open-source media system. The code-quality.yml GitHub Actions workflow in jellyfin/jellyfin-ios is…
CVE-2025-20282 — Critical (CVSS 10.0): A vulnerability in an internal API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to…
CVE-2025-0505 — Critical (CVSS 10.0): On Arista CloudVision systems (virtual or physical on-premise deployments), Zero Touch Provisioning can be used to gain…
CVE-2023-48418 — Critical (CVSS 10.0): In checkDebuggingDisallowed of DeviceVersionFragment.java, there is a possible way to access adb before SUW…
CVE-2023-48419 — Critical (CVSS 10.0): An attacker in the wifi vicinity of a target Google Home can spy on the victim, resulting in Elevation of Privilege
CVE-2023-31273 — Critical (CVSS 10.0): Protection mechanism failure in some Intel DCM software before version 5.2 may allow an unauthenticated user to…

Browse all CWE-269 (Improper Privilege Management) vulnerabilities →