# CVE-2026-57196: Asterisk reflected cross-site scripting in phone provisioning

Source: https://junglewise.ai/threats/cve-2026-57196-asterisk-is-an-open-source-private-branch-exchange-and-telephony  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-26. Updated: 2026-10-26  
License: CC BY 4.0 with a link back

CVE-2026-57196 · Severity: info · Published 2026-10-26

Asterisk is an open-source telephone system that manages business voice communications. An unauthenticated attacker can inject malicious scripts into phone provisioning error pages to steal authentication cookies from administrators and take over their accounts. Multiple security features must be manually enabled for the vulnerability to be exploitable, and the attacker must trick a user into clicking a link.

Technologies: [Asterisk](https://junglewise.ai/threats/technologies/asterisk), [Asterisk Certified Asterisk](https://junglewise.ai/threats/technologies/certified-asterisk). Vendors: [Asterisk](https://junglewise.ai/threats/vendors/asterisk).

## Quick answers

**Is CVE-2026-57196 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-57196 being exploited in the wild.

**How severe is CVE-2026-57196?** Informational severity, published 26 October 2026.

**Which products and versions are affected?** Asterisk before 20.20.1, 21.12.3, 22.10.1, 23.4.1; Asterisk Certified Asterisk before 20.7-cert11, 22.8-cert3.

**Is there a fix for CVE-2026-57196?** Yes: fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1; Certified Asterisk 20.7-cert11, 22.8-cert3. Until then: Ensure the HTTP server, Asterisk Manager Interface (AMI), and AMI access via HTTP remain disabled (the default configuration). If these services must be enabled, restrict HTTP server access via firewall rules to trusted networks only, as the HTTP server binds to 127.0.0.1 by default. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-57196 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-57196?** Check whether you run Asterisk or Asterisk Certified Asterisk at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1; Certified Asterisk 20.7-cert11, 22.8-cert3

Ensure the HTTP server, Asterisk Manager Interface (AMI), and AMI access via HTTP remain disabled (the default configuration). If these services must be enabled, restrict HTTP server access via firewall rules to trusted networks only, as the HTTP server binds to 127.0.0.1 by default.

## Technical details

A reflected cross-site scripting (XSS) vulnerability exists in Asterisk's HTTP error page generation for phone provisioning (res_phoneprov module). The ast_http_create_response() function fails to escape HTML metacharacters in the error text parameter before inserting it into the response body, allowing injection of arbitrary JavaScript. An attacker can craft a malicious URI containing script tags that, when visited by an authenticated administrator, executes in their browser context and exfiltrates their AMI session cookie for account impersonation.

## Affected products

- Asterisk Asterisk before 20.20.1, 21.12.3, 22.10.1, 23.4.1
- Asterisk Certified Asterisk before 20.7-cert11, 22.8-cert3

## Timeline

- 2026-10-26: disclosed
- 2026-10-26: patched

## References

- [https://github.com/asterisk/asterisk/commit/4373f8174bf71c467fc9db96036126d30425b9e8](https://github.com/asterisk/asterisk/commit/4373f8174bf71c467fc9db96036126d30425b9e8)
- [https://github.com/asterisk/asterisk/commit/4b360a61d649a7c12b1021aa554642322ee28c10](https://github.com/asterisk/asterisk/commit/4b360a61d649a7c12b1021aa554642322ee28c10)

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- [Asterisk authorization bypass in ARI REST-over-WebSocket](https://junglewise.ai/threats/cve-2026-57200-asterisk-is-an-open-source-private-branch-exchange-and-telephony)
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- [Asterisk privilege escalation in REST Interface](https://junglewise.ai/threats/cve-2026-57202-asterisk-is-an-open-source-private-branch-exchange-and-telephony)