# CVE-2026-57193: Asterisk LDAP filter injection in SIP username

Source: https://junglewise.ai/threats/cve-2026-57193-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-2026-57193 · Severity: info · Published 2026-10-26

Asterisk is an open source phone system and call handling toolkit. When configured to use LDAP for user lookup (a non-default setting), an attacker can craft specially formatted SIP calls that inject LDAP filter commands, allowing them to query the LDAP directory and extract sensitive information without authentication.

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-2026-57193 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-57193 being exploited in the wild.

**How severe is CVE-2026-57193?** Informational severity, published 26 October 2026.

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

**Is there a fix for CVE-2026-57193?** Yes: fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1; Certified Asterisk 20.7-cert11, 22.8-cert3. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-57193 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-57193?** 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

## Technical details

The LDAP realtime driver (res_config_ldap) concatenates user-supplied SIP From header usernames directly into LDAP filter queries without escaping RFC 4515 special characters (*, (, ), \). An unauthenticated attacker can send crafted SIP packets with LDAP filter metacharacters in the username to execute arbitrary LDAP queries. The vulnerability requires LDAP realtime backend configuration and the res_config_ldap module to be loaded.

## Affected products

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

## Timeline

- 2026-10-26: disclosed

## References

- [https://github.com/asterisk/asterisk/commit/04aa482212e43b292817444eb4de35499f4b1568](https://github.com/asterisk/asterisk/commit/04aa482212e43b292817444eb4de35499f4b1568)
- [https://github.com/asterisk/asterisk/commit/14968f2f440ea0dd983caa4f477237a5224904dd](https://github.com/asterisk/asterisk/commit/14968f2f440ea0dd983caa4f477237a5224904dd)

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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)