SB2025121089 - Denial of service in Envoy
Published: December 10, 2025
Security Bulletin ID
SB2025121089
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Use-after-free (CVE-ID: N/A)
The vulnerability allows a remote attacker to perform a denial of service attack
The vulnerability exists due to a use-after-free error during the ares_getaddrinfo query lifecycle when processing a specific sequence of DNS responses. A remote attacker can send a specially crafted DNS response to the application and perform a denial of service attack.
Note, the vulnerability exists due to usage of the vulnerable c-ares library - #VU119383 (CVE-2025-6240).
Remediation
Install update from vendor's website.