Quick answers
- Is CVE-2026-57189 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-57189 being exploited in the wild.
- How severe is CVE-2026-57189?
- Informational severity, published 27 October 2026.
- Which products and versions are affected?
- Asterisk versions prior to 20.20.1, 21.12.3, 22.10.1, and 23.4.1; Certified Asterisk prior to 20.7-cert11 and 22.8-cert3.
- Is there a fix for CVE-2026-57189?
- 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: Disable the textsupport option in chan_sip channel driver configuration, or migrate to a newer Asterisk version where chan_sip has been removed. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-57189 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-57189?
- Check whether you run 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
Disable the textsupport option in chan_sip channel driver configuration, or migrate to a newer Asterisk version where chan_sip has been removed.
Technical details
A buffer overrun exists in res_rtp_asterisk.c's handling of T.140 RED (redundant) frames during generation accumulation. An authenticated attacker can send malformed packets that cause integer wrapping in the rtp_red->len array, writing out-of-bounds in either the t140red_data or buf_data buffers. This requires the chan_sip channel driver and its textsupport option to be enabled (textsupport defaults to disabled).
Affected products
- Asterisk Asterisk versions prior to 20.20.1, 21.12.3, 22.10.1, and 23.4.1; Certified Asterisk prior to 20.7-cert11 and 22.8-cert3
Timeline
- 2026-10-27: disclosed