CVE-2025-12206Public exploit

Local service crash via null configuration expression

Published Oct 27, 2025 · Updated Oct 27, 2025

NULL pointer dereference in Kamailio SIP Server 5.5 allows local users to crash the service through a crafted configuration file. The rve_is_constant function in src/core/rvalue.c dereferences a null pointer while processing an attacker-supplied configuration expression. Exploitation requires local access and the ability to replace a Kamailio configuration file; the project disputes the claim and states that the published trigger file was unavailable.

CVSS severity5.5
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Kamailio SIP Server 5.5 allows local users to crash the service through a crafted configuration file. The rve_is_constant function in src/core/rvalue.c dereferences a null pointer while processing an attacker-supplied configuration expression. Exploitation requires local access and the ability to replace a Kamailio configuration file; the project disputes the claim and states that the published trigger file was unavailable.

The record

CVE
CVE-2025-12206
Published
Oct 27, 2025
Updated
Oct 27, 2025
Vendor
Kamailio Project
Product
Kamailio SIP Server
Classifications
CWE-476, CWE-404, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 27, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Kamailio Project · Kamailio SIP Serverversion=5.5

Published CVSS scores

3.3VulDB CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
1.7VulDB CNAAV:L/AC:L/Au:S/C:N/I:N/A:P
3.3VulDB CNACVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
4.8VulDB CNACVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
CWE-404Improper Resource Shutdown or Release
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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