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TI-2026-81564 Aliases CVE-2026-57192

Out-of-bounds write in Asterisk Codec2 decoder

Priority LOW 28CWE-125Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-125 and the CVSS impact.

Summary

Asterisk before 20.20.1, from 21.0.0-pre1 before 21.12.3, from 22.0.0-pre1 before 22.10.1 and from 23.0.0-pre1 before 23.4.1, and Certified Asterisk before 20.7-cert11 and from 22.8-cert1-pre1 before 22.8-cert3, are affected. A floor/ceil sample-count mismatch in the Codec2 decoder causes an out-of-bounds write (CWE-787) that leads to a heap buffer overflow. An authenticated attacker who passes SIP authentication and establishes a call using Codec2 can trigger it by sending crafted Codec2 audio packets.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

Description from the CNA

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 authenticated attacker may cause a heap buffer overflow through an out-of-bounds write in the `Codec2` decoder caused by a `floor/ceil sample-count mismatch`. The `codec_codec2` module must be loaded and `Codec2` must be configured on the attacked endpoint. The attacker must pass SIP authentication by username/password or `source IP address matching`, establish a call using `Codec2`, and send carefully crafted `Codec2` audio packets. 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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0065 51st percentileScored 2026-11-07
Fix Fixed asterisk (asterisk): 20.20.1, 21.12.3, 22.10.1 +1certified-asterisk (asterisk): 20.7-cert11, 22.8-cert3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
asteriskasteriskbefore 20.20.1; 21.0.0-pre1 to before 21.12.3; 22.0.0-pre1 to before 22.10.1; 23.0.0-pre1 to before 23.4.120.20.1, 21.12.3, 22.10.1, 23.4.1Patch availableCNA
asteriskcertified-asteriskbefore 20.7-cert11; 22.8-cert1-pre1 to before 22.8-cert320.7-cert11, 22.8-cert3Patch availableCNA
  • asterisk Vendorasterisk Affected before 20.20.1; 21.0.0-pre1 to before 21.12.3; 22.0.0-pre1 to before 22.10.1; 23.0.0-pre1 to before 23.4.1 Fixed in 20.20.1, 21.12.3, 22.10.1, 23.4.1 Patch available CNA
  • certified-asterisk Vendorasterisk Affected before 20.7-cert11; 22.8-cert1-pre1 to before 22.8-cert3 Fixed in 20.7-cert11, 22.8-cert3 Patch available CNA

Remediation

Upgrade Asterisk to 20.20.1, 21.12.3, 22.10.1 or 23.4.1, and upgrade Certified Asterisk to 20.7-cert11 or 22.8-cert3.

Written with Claude Haiku 5.5 from the sources below · 2026-11-03

  • Fix · CNA asterisk (asterisk) Fixed in 20.20.1, 21.12.3, 22.10.1, 23.4.1
  • Fix · CNA certified-asterisk (asterisk) Fixed in 20.7-cert11, 22.8-cert3

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-27 Threatist record created from CVE-2026-57192
  2. 2026-10-28 Priority changed: MEDIUM → LOW
  3. 2026-11-02 Affected versions changed · Red Hat
  4. 2026-11-02 CVSS score added · Red Hat
  5. 2026-11-03 CISA SSVC decision points changed

References

Other 15

  • TI-2025-30244 Using malformed From header can forge identity with ";" or NULL in name portion CVSS 3.1HIGH 7.7
  • TI-2023-27195 Asterisk susceptible to Denial of Service via DTLS Hello packets during call initiation CVSS 3.1HIGH 7.5
  • TI-2024-28351 Asterisk allows `Write=originate` as sufficient permissions for code execution / `System()` dialplan CVSS 3.1HIGH 8.8
  • TI-2025-00959 Asterisk Unsafe Shell Sourcing in safe_asterisk Leads to Local Privilege Escalation CVSS 4.0HIGH 7.0
  • TI-2025-34699 Asterisk remotely exploitable leak of RTP UDP ports and internal resources CVSS 3.1MEDIUM 6.5
  • TI-2025-31747 Asterisk is Vulnerable to Remote DoS and possible RCE Attacks During Memory Allocation CVSS 3.1MEDIUM 6.5
See all 87 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences