CyberSecBulletin
CVE-2026-57186NVD status: Awaiting Analysis

asterisk: Numeric Range Comparison Without Minimum Check

Published Updated By the CyberSecBulletin desk

CVE-2026-57186 is a high-severity numeric range comparison without minimum check vulnerability in asterisk, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected asterisk versions: >= 21.0.0-pre1, < 21.12.3; >= 22.0.0-pre1, < 22.10.1; >= 23.0.0-pre1, < 23.4.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.6% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of asterisk you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Asteriskasterisk>= 21.0.0-pre1, < 21.12.3; >= 22.0.0-pre1, < 22.10.1; >= 23.0.0-pre1, < 23.4.1Not stated
Asteriskcertified-asterisk>= 22.8-cert1-pre1, < 22.8-cert3Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (github.com).

Official description

Asterisk is an open source private branch exchange and telephony toolkit. From 21.0.0-pre1 until Asterisk 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 22.8-cert3, the `chan_ooh323` `Q.931 party-number parser` lacks the `CVE-2022-37325` fix because that fix was never forward-ported from Asterisk 20 to later versions. Malformed Q.931 elements in an `OOH323 request` can therefore crash Asterisk. This issue affects Asterisk versions greater than 20. The `chan_ooh323` addon channel driver must be explicitly compiled and installed, which is not the default, and its port must be publicly reachable. This issue is fixed in Asterisk 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 22.8-cert3.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Numeric Range Comparison Without Minimum Check

The product checks a value to ensure that it is less than or equal to a maximum, but it does not also verify that the value is greater than or equal to the minimum.

How developers prevent this class of flaw

  • If the number to be used is always expected to be positive, change the variable type from signed to unsigned or size_t.
  • If the number to be used could have a negative value based on the specification (thus requiring a signed value), but the number should only be positive to preserve code correctness, then include a check to ensure that the value is positive.

More Numeric Range Comparison Without Minimum Check vulnerabilities (CWE-839)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in asterisk

All asterisk vulnerabilities

Recent Numeric Range Comparison Without Minimum Check vulnerabilities

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