Asterisk up to 18.9-cert16/18.26.3 improper validation of syntactic correctness of input

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.3$0-$5k0.00

Summaryinfo

A vulnerability was found in Asterisk up to 18.9-cert16/18.26.3. It has been classified as problematic. This impacts an unknown function. This manipulation causes improper validation of syntactic correctness of input. This vulnerability is handled as CVE-2025-54995. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Asterisk up to 18.9-cert16/18.26.3 and classified as problematic. Affected by this vulnerability is an unknown code block. The manipulation with an unknown input leads to a improper validation of syntactic correctness of input vulnerability. The CWE definition for the vulnerability is CWE-1286. The product receives input that is expected to be well-formed - i.e., to comply with a certain syntax - but it does not validate or incorrectly validates that the input complies with the syntax. As an impact it is known to affect availability. The summary by CVE is:

Asterisk is an open source private branch exchange and telephony toolkit. Prior to versions 18.26.4 and 18.9-cert17, RTP UDP ports and internal resources can leak due to a lack of session termination. This could result in leaks and resource exhaustion. This issue has been patched in versions 18.26.4 and 18.9-cert17.

The advisory is shared at github.com. This vulnerability is known as CVE-2025-54995 since 08/04/2025. The exploitation appears to be easy. The attack can be launched remotely. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 269985 (Debian dla-4326 : asterisk - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 18.9-cert17 or 18.26.4 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (269985), EUVD (EUVD-2025-26134) and CERT Bund (WID-SEC-2025-1926). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Debian Linux
  • Gentoo Linux
  • Open Source Asterisk

Productinfo

Type

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper validation of syntactic correctness of input
CWE: CWE-1286 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 269985
Nessus Name: Debian dla-4326 : asterisk - security update

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Asterisk 18.9-cert17/18.26.4

Timelineinfo

08/04/2025 CVE reserved
08/28/2025 +24 days Advisory disclosed
08/28/2025 +0 days VulDB entry created
01/26/2026 +151 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2025-54995 (🔒)
GCVE (CVE): GCVE-0-2025-54995
GCVE (VulDB): GCVE-100-321781
EUVD: 🔒
CERT Bund: WID-SEC-2025-1926 - Asterisk: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 08/28/2025 17:20
Updated: 01/26/2026 14:30
Changes: 08/28/2025 17:20 (62), 08/28/2025 22:08 (1), 10/11/2025 07:42 (2), 01/26/2026 14:30 (7)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Want to know what is going to be exploited?

We predict KEV entries!