CVE Catalog

CVE-2026-57194

MediumCVSS 5.9
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.44%

38th percentile - higher than 38% of all known CVEs

Summary

An out-of-bounds write in the chan_unistim module's DIALPAGE digit handling can overflow the phone_number field and crash Asterisk when a crafted incoming request packet is sent. The chan_unistim module must be loaded and configured with a reachable UNISTIM UDP port, and the attacker must register as a configured phone MAC or use an equivalent autoprovisioning path. The 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.

Risk Assessment

An attacker can remotely crash the telephony PBX, causing an outage of telecommunication services. This can disrupt organizational communications and affect service availability.

Recommendation

Update Asterisk to one of the fixed versions (20.20.1, 21.12.3, 22.10.1, 23.4.1 or the corresponding Certified version). If chan_unistim is not used, disable it and restrict access to the UNISTIM UDP port.

Other vulnerabilities in Asterisk

See all
Original NVD description (English source)

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, an out-of-bounds write in `chan_unistim` `DIALPAGE` digit handling can overflow the `phone_number` field and crash Asterisk when an attacker sends a carefully crafted incoming request packet. The `chan_unistim` module must be loaded and configured with a valid `UNISTIM UDP port` that the attacker can reach. The attacker must register as a configured `phone MAC`, or the deployment must have an equivalent `production/autoprovisioning` path that allows the client to reach the main page. 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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS