Description
Asterisk is an open source private branch exchange and telephony toolkit. In affected deployments, an authenticated attacker may cause a `T.140 RED` heap buffer overflow using carefully crafted packets, potentially allowing remote code execution or causing Asterisk to crash. The `chan_sip` channel driver must be installed and configured, and its `textsupport` option must be enabled; `textsupport` defaults to no. `The chan_sip driver was deprecated in Asterisk 20 and completely removed in all later versions.` Repository comparisons verify patch containment in Asterisk 20.20.1, 21.12.3, 22.10.1 and 23.4.1, and Certified Asterisk 20.7-cert11 and 22.8-cert3. The affected release-track scope remains unresolved: structured metadata includes later release tracks even though the advisory says the required `chan_sip` driver was removed there.
References10
- github.com/asterisk/asterisk/commit/0601c33d4edf8c8f221de91cead…
- github.com/asterisk/asterisk/commit/111487298a954a029daae941eac…
- github.com/asterisk/asterisk/commit/536218a86b797996e8e8844deac…
- github.com/asterisk/asterisk/commit/a89b61d7c756f816c7fa5327ead…
- github.com/asterisk/asterisk/commit/eaa108c68a32c080d7a168ef1d8…
- github.com/asterisk/asterisk/commit/eef894282be203cb9e6d8e9692e…
- github.com/asterisk/asterisk/commit/fde69a1f3ff17f507a1578ae27b…
- github.com/asterisk/asterisk/releases/tag/20.20.1
- github.com/asterisk/asterisk/releases/tag/21.12.3
- github.com/asterisk/asterisk/releases/tag/22.10.1
Metrics
- CVSS 4.0
-
2.3
LOW
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 58 · as of 5 November 2026
- CWE
- CWE-122
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.