CVE-2026-39863 — AI Deep Analysis Summary

Q: What is this vulnerability? (Essence + Consequences)

🚨 **Nature**: The Kamailio SIP signaling server contains a **buffer error** (out-of-bounds access). 💥 **Consequence**: Directly causes **Denial of Service (DoS)**, rendering the service unavailable.

Q: Root Cause? (CWE/Flaw)

🔍 **Root Cause**: **Out-of-bounds Access**. 📉 **CWE Mapping**: A typical buffer management defect leading to uncontrolled memory read/write operations.

Q: Who is affected? (Versions/Components)

📦 **Affected Component**: **Kamailio** (open-source SIP signaling server). ⚠️ **High-Risk Versions**: • Versions before 6.1.1 • Versions before 6.0.6 • Versions before 5.8.8

Q: Is there a public Exp? (PoC/Wild Exploitation)

📜 **Existing Exploit**: Data shows **PoCs are empty**. 🌍 **In-the-Wild Exploitation**: Not mentioned. ⚠️ **Note**: Although no public PoC exists, the low exploitation barrier implies a **very high 0-day risk**.

Q: Is it fixed officially? (Patch/Mitigation)

🛡️ **Official Fix**: **Released**. 📅 **Release Date**: 2026-04-08. 🔗 **Reference Link**: GitHub Advisory (GHSA-2wj4-f825-2h2f). ✅ **Recommendation**: Immediately upgrade to 6.1.1+ / 6.0.6+ / 5.8.8+.

Updated Jul 23, 2026 CVSS 7.5 · High

This is a summary of the AI-generated 10-question deep analysis. The full version (longer answers, follow-up Q&A, related CVEs) requires login. Read the full analysis →

Q1What is this vulnerability? (Essence + Consequences)

🚨 **Nature**: The Kamailio SIP signaling server contains a **buffer error** (out-of-bounds access).<br>💥 **Consequence**: Directly causes **Denial of Service (DoS)**, rendering the service unavailable.

Q2Root Cause? (CWE/Flaw)

🔍 **Root Cause**: **Out-of-bounds Access**.<br>📉 **CWE Mapping**: A typical buffer management defect leading to uncontrolled memory read/write operations.

Q3Who is affected? (Versions/Components)

📦 **Affected Component**: **Kamailio** (open-source SIP signaling server).<br>⚠️ **High-Risk Versions**:<br>• Versions before 6.1.1<br>• Versions before 6.0.6<br>• Versions before 5.8.8

Q4What can hackers do? (Privileges/Data)

🛑 **Attacker Capabilities**: Limited to **Denial of Service**.<br>🚫 **No Privilege Escalation**: CVSS shows C:N/I:N; cannot steal data or tamper with configurations.<br>📉 **Impact**: A:H (High Availability Impact), servi…

Read full answer (login)

Q5Is exploitation threshold high? (Auth/Config)

🚪 **Exploitation Barrier**: **Low**.<br>✅ **No Authentication Required** (PR:N)<br>✅ **No User Interaction Required** (UI:N)<br>✅ **Network Attack Vector** (AV:N)<br>🎯 **Low Attack Complexity** (AC:L), remotely triggerab…

Read full answer (login)

Q6Is there a public Exp? (PoC/Wild Exploitation)

📜 **Existing Exploit**: Data shows **PoCs are empty**.<br>🌍 **In-the-Wild Exploitation**: Not mentioned.<br>⚠️ **Note**: Although no public PoC exists, the low exploitation barrier implies a **very high 0-day risk**.

Q7How to self-check? (Features/Scanning)

🔎 **Self-Check Method**:<br>1. Check if the Kamailio version is within the **high-risk range** mentioned above.<br>2. Monitor SIP signaling traffic for anomalies, such as malformed packets targeting buffers.<br>3.…

Read full answer (login)

Q8Is it fixed officially? (Patch/Mitigation)

🛡️ **Official Fix**: **Released**.<br>📅 **Release Date**: 2026-04-08.<br>🔗 **Reference Link**: GitHub Advisory (GHSA-2wj4-f825-2h2f).<br>✅ **Recommendation**: Immediately upgrade to 6.1.1+ / 6.0.6+ / 5.8.8+.

Q9What if no patch? (Workaround)

🚧 **Temporary Mitigation**:<br>1. **Network Isolation**: Restrict SIP ports to be accessible only from trusted IPs.<br>2. **WAF/IPS**: Deploy rules to intercept abnormal SIP packet lengths or formats.<br>3.…

Read full answer (login)

Q10Is it urgent? (Priority Suggestion)

🔥 **Priority**: **High**.<br>💡 **Reasoning**:<br>• Triggerable remotely without authentication.<br>• Causes complete service unavailability (DoS).<br>• Core component of SIP infrastructure with a broad impact scope.<br>👉…

Read full answer (login)

Continue exploring

Vulnerability detail Full AI analysis (login) kamailio CWE-119