How severe is CVE-2025-25566?

CVE-2025-25566 has a CVSS 3.x base score of 5.6, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2025-25566 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-25566?

CVE-2025-25566 affects Softether Vpn. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-25566?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-25566 have an EU (EUVD) identifier?

Yes. CVE-2025-25566 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-7672.

When was CVE-2025-25566 published?

CVE-2025-25566 was published on 2025-03-12 and last updated on 2026-06-17.

CVE-2025-25566

CVE-2025-25566 is a medium-severity vulnerability in Softether Vpn with a CVSS 3.x base score of 5.6. 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-401.

Key facts

Severity: Medium (CVSS 3.x base score 5.6)
EPSS exploit prediction: 0% (21st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-7672
Weakness: CWE-401
Affected product: Softether Vpn
Published: 2025-03-12
Last modified: 2026-06-17

Description

Memory Leak vulnerability in SoftEtherVPN 5.02.5187 allows an attacker to cause a denial of service via the UnixMemoryAlloc function. NOTE: the Supplier disputes this because the behavior is limited to a single allocation of a few hundred bytes with a command-line tool.

Frequently asked questions

What is CVE-2025-25566?: Memory Leak vulnerability in SoftEtherVPN 5.02.5187 allows an attacker to cause a denial of service via the UnixMemoryAlloc function. NOTE: the Supplier disputes this because the behavior is limited to a single allocation of a few hundred bytes with a command-line tool.
How severe is CVE-2025-25566?: CVE-2025-25566 has a CVSS 3.x base score of 5.6, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2025-25566 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-25566?: CVE-2025-25566 affects Softether Vpn. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-25566?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-25566 have an EU (EUVD) identifier?: Yes. CVE-2025-25566 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-7672.
When was CVE-2025-25566 published?: CVE-2025-25566 was published on 2025-03-12 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:softether:vpn:5.02.5187:*:*:*:*:*:*:*

More vulnerabilities in Softether Vpn

CVE-2025-25568 — Critical (CVSS 9.8): SoftEtherVPN 5.02.5187 is vulnerable to Use after Free in the Command.c file via the CheckNetworkAcceptThread function.…
CVE-2025-25567 — Critical (CVSS 9.8): SoftEther VPN 5.02.5187 is vulnerable to Buffer Overflow in Internat.c via the UniToStrForSingleChars function. NOTE:…
CVE-2025-25565 — Critical (CVSS 9.8): SoftEther VPN 5.02.5187 is vulnerable to Buffer Overflow in the Command.c file via the PtMakeCert and PtMakeCert2048…
CVE-2023-27395 — Critical (CVSS 9.0): A heap-based buffer overflow vulnerability exists in the vpnserver WpcParsePacket() functionality of SoftEther VPN…
CVE-2023-32634 — High (CVSS 7.8): An authentication bypass vulnerability exists in the CiRpcServerThread() functionality of SoftEther VPN 5.01.9674 and…
CVE-2023-25774 — High (CVSS 7.5): A denial-of-service vulnerability exists in the vpnserver ConnectionAccept() functionality of SoftEther VPN 5.02. A set…

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