CVE-2025-54995Known exploitationPublic exploitNetwork attack vector

Service interruption via unterminated PJSIP sessions

Published Aug 28, 2025 · Updated Nov 3, 2025

Resource exhaustion in Asterisk 18.26.3 and earlier or 18.9-cert16 and earlier allows remote authenticated users to interrupt service via SIP. A malformed static Via branch prevents normal BYE-driven teardown after ACK, so PJSIP retains RTP UDP ports and module resources after the connection closes. Access to an accepting PJSIP endpoint is required, and repeated calls exhaust the RTP port range until the PBX becomes inoperable.

CVSS severity6.5
Medium
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Asterisk 18.26.3 and earlier or 18.9-cert16 and earlier allows remote authenticated users to interrupt service via SIP. A malformed static Via branch prevents normal BYE-driven teardown after ACK, so PJSIP retains RTP UDP ports and module resources after the connection closes. Access to an accepting PJSIP endpoint is required, and repeated calls exhaust the RTP port range until the PBX becomes inoperable.

The record

CVE
CVE-2025-54995
Published
Aug 28, 2025
Updated
Nov 3, 2025
Vendor
Asterisk
Product
Asterisk
Classifications
CWE-1286, CWE-400, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 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=< 18.26.4
  2. Affected versionversion=< 18.9-cert17

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Asterisk · Asteriskversion=< 18.26.4; version=< 18.9-cert17

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-1286Improper Validation of Syntactic Correctness of Input
CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

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

Reported exploitation

Technologies

Your stack

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Your stack

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