Heap-based buffer overflow in SoftEther VPN
Priority MEDIUM 44CWE-122Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-122 and the CVSS impact.
Summary
A heap-based buffer overflow vulnerability exists in the vpnserver WpcParsePacket() functionality of SoftEther VPN 4.41-9782-beta, 5.01.9674 and 5.02. A specially crafted network packet can lead to arbitrary code execution. An attacker can perform a man-in-the-middle attack to trigger this vulnerability.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01543 75th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| SoftEther VPN | SoftEther VPN | 4.41-9782-beta; 5.01.9674; 5.02 | — | No fix listed | CNA |
- SoftEther VPN VendorSoftEther VPN Affected 4.41-9782-beta; 5.01.9674; 5.02 Fixed in — No fix listed CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:softether:vpn:4.41-9782:beta:*:*:*:*:*:* | 4.41-9782 beta | Vulnerable | SoftEther VPN |
| cpe:2.3:a:softether:vpn:5.01.9674:*:*:*:*:*:*:* | 5.01.9674 | Vulnerable | SoftEther VPN |
| cpe:2.3:a:softether:vpn:5.02:*:*:*:*:*:*:* | 5.02 | Vulnerable | SoftEther VPN |
- cpe:2.3:a:softether:vpn:4.41-9782:beta:*:*:*:*:*:* Versions 4.41-9782 beta Vulnerable ·SoftEther VPN
- cpe:2.3:a:softether:vpn:5.01.9674:*:*:*:*:*:*:* Versions 5.01.9674 Vulnerable ·SoftEther VPN
- cpe:2.3:a:softether:vpn:5.02:*:*:*:*:*:*:* Versions 5.02 Vulnerable ·SoftEther VPN
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2023-27395
- 2026-10-03 Alias added: GHSA-33mh-qwc8-jxxx
References
More SoftEther VPN Vpn vulnerabilities
- TI-2025-19052 SoftEtherVPN 5.02.5187 is vulnerable to Use after Free in the Command.c file via the… CVSS 3.1CRITICAL 9.8
- TI-2025-19051 SoftEther VPN 5.02.5187 is vulnerable to Buffer Overflow in Internat.c via the… CVSS 3.1CRITICAL 9.8
- TI-2025-19049 SoftEther VPN 5.02.5187 is vulnerable to Buffer Overflow in the Command.c file via the… CVSS 3.1CRITICAL 9.8
- TI-2023-15913 An authentication bypass vulnerability exists in the CiRpcServerThread() functionality of… CVSS 3.1HIGH 7.8
- TI-2023-12241 An authentication bypass vulnerability exists in the CiRpcAccepted() functionality of… CVSS 3.1HIGH 7.8
- TI-2023-08590 Infinite loop in SoftEther VPN CVSS 3.1MEDIUM 5.9
Sources
- CVE-2023-27395 · CVE Program
- CVE-2023-27395 · NVD
- FIRST EPSS
- GHSA-33mh-qwc8-jxxx · GitHub Advisory Database · CC BY 4.0
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