CVE-2026-57187 — Asterisk: Heap-use-after-free in Asterisk PJSIP TCP/SDP handling when TCP connection closes during SDP processing
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-use-after-free in `PJSIP TCP/SDP` handling by sending a `SIP INVITE` over a connection-oriented transport and disconnecting before Asterisk responds with the `200 OK`. So far, the crash has only been reproduced when Asterisk is built with `Address Sanitizer`, which detects the issue. `Address Sanitizer` is a development tool with significant performance overhead and, according to the maintainer, is not used in production systems. 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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+6
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Asterisk Asterisk, Asterisk Certified-asterisk).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Asterisk | Asterisk | version < 20.20.1version >= 21.0.0-pre1, < 21.12.3version >= 22.0.0-pre1, < 22.10.1version >= 23.0.0-pre1, < 23.4.1 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Asterisk | Certified-asterisk | version < 20.7-cert11version >= 22.8-cert1-pre1, < 22.8-cert3 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.1 | CVSS 4.0 | High | — | — | security-advisories@github.com via NIST National Vulnerability Database |
| 7.1 | CVSS 4.0 | High | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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 (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Source status changed · Received → Awaiting Analysis
- Affected products added · asterisk/asterisk, asterisk/certified-asterisk
- Record published
- CVSS changed · 7.1
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 26, 2026 – Oct 26, 2026
- 1× Official description updated · Oct 26, 2026 – Oct 26, 2026
References
15 on the record
- github.com/asterisk/asterisk/commit/27b9544b32f059a4f614169243eaa7559f622aa0
- github.com/asterisk/asterisk/releases/tag/certified-20.7-cert11
- github.com/asterisk/asterisk/commit/d4e30005940f86942745bcc64f34748d69870247
- github.com/asterisk/asterisk/releases/tag/23.4.1
- github.com/asterisk/asterisk/commit/b7ba85458796ef54b471017287c7806095dbda76
- github.com/asterisk/asterisk/commit/9e0386c6d259f0c7499d52499d9891bee8a494fa
- github.com/asterisk/asterisk/releases/tag/certified-22.8-cert3
- github.com/asterisk/asterisk/releases/tag/21.12.3
- github.com/asterisk/asterisk/commit/6e1f4df744369d66ea6f412e355d819b2a7bf26c
- github.com/asterisk/asterisk/tree/24.0.0-pre1
- github.com/asterisk/asterisk/releases/tag/20.20.1
- github.com/asterisk/asterisk/commit/f1e47621472bb3d8ad71f32823f5ca986e008437
- github.com/asterisk/asterisk/security/advisories/GHSA-g8q2-p36q-94f6
- github.com/asterisk/asterisk/commit/0f076168e0be31ebee37762192d0ee049e9c0d42
- github.com/asterisk/asterisk/releases/tag/22.10.1
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-57203 Asterisk: Local privilege escalation through ast_loggrabber's world-writable helper location 13m
- High CVE-2026-57190 Asterisk: SQL Injection in cel_pgsql and cel_tds via CELGenUserEvent eventtype Field 13m
- High CVE-2026-57191 Asterisk: Stack buffer overflow in MWI NOTIFY Message-Account parsing 13m
- Low CVE-2026-57199 Asterisk: Asterisk app_sms.c copies externally controlled SMS lengths into fixed in-struct buffers 13m
- High CVE-2026-57186 Asterisk: CVE-2022-37325 fix is absent from current chan_ooh323 Q.931 party-number parser 13m
- High CVE-2026-57195 Asterisk: NULL Pointer Dereference in HTTP AMI Digest Authentication 1h
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-57187 is "Asterisk: Heap-use-after-free in Asterisk PJSIP TCP/SDP handling when TCP connection closes during SDP processing", rated High. It affects Asterisk (Asterisk); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.1 describes technical severity. EPSS 0.48% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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