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TI-2026-28744 Aliases CVE-2026-39863

Kamailio Core: TCP Data Processing Vulnerability

Priority LOW 39CWE-119Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-119 and the CVSS impact.

Summary

Kamailio is an open source implementation of a SIP Signaling Server. Prior to 6.1.1, 6.0.6, and 5.8.8, an out-of-bounds access in the core of Kamailio (formerly OpenSER and SER) allows remote attackers to cause a denial of service (process crash) via a specially crafted data packet sent over TCP. The issue impacts Kamailio instances having TCP or TLS listeners. This vulnerability is fixed in 5.1.1, 6.0.6, and 5.8.8.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00471 41st percentileScored 2026-11-07
Fix Fixed kamailio (kamailio): 5.8.8, 6.0.6, 6.1.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
kamailiokamailiobefore 5.8.8; 6.0.0 to before 6.0.6; 6.1.0 to before 6.1.15.8.8, 6.0.6, 6.1.1Patch availableCNA
  • kamailio Vendorkamailio Affected before 5.8.8; 6.0.0 to before 6.0.6; 6.1.0 to before 6.1.1 Fixed in 5.8.8, 6.0.6, 6.1.1 Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:kamailio:kamailio:*:*:*:*:*:*:*:*before 5.8.8; 6.0.0 to before 6.0.6Vulnerablekamailio
cpe:2.3:a:kamailio:kamailio:6.1.0:*:*:*:*:*:*:*6.1.0Vulnerablekamailio
  • cpe:2.3:a:kamailio:kamailio:*:*:*:*:*:*:*:* Versions before 5.8.8; 6.0.0 to before 6.0.6 Vulnerable ·kamailio
  • cpe:2.3:a:kamailio:kamailio:6.1.0:*:*:*:*:*:*:* Versions 6.1.0 Vulnerable ·kamailio

Remediation

  • Fix · CNA kamailio (kamailio) Fixed in 5.8.8, 6.0.6, 6.1.1

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-39863
  2. 2026-10-25 Priority changed: MEDIUM → LOW

References

Advisory 1

  • TI-2020-16681 The Kamailio SIP before 5.5.0 server mishandles INVITE requests with duplicated fields… CVSS 3.1CRITICAL 9.8
  • TI-2018-06372 A Buffer Overflow issue was discovered in Kamailio before 4.4.7, 5.0.x before 5.0.6, and… CVSS 3.0CRITICAL 9.8
  • TI-2018-10598 In Kamailio before 5.0.7 and 5.1.x before 5.1.4, a crafted SIP message with a double "To"… CVSS 3.0CRITICAL 9.8
  • TI-2016-02145 Heap-based buffer overflow in the encode_msg function in encode_msg.c in the SEAS module… CVSS 3.0CRITICAL 9.8
  • TI-2025-11190 Kamailio Grammar Rule cfg.y yyerror_at null pointer dereference CVSS 4.0MEDIUM 4.8
  • TI-2025-11189 Kamailio rvalue.c rve_is_constant null pointer dereference CVSS 4.0MEDIUM 4.8
See all 16 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences