MediumFix available
asterisk — security advisory
An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.
- Products
- asterisk
- Affected versions
- Not specified
- Fixed versions
- 16.16.1-r0, 18.2.1-r0
- CVEs
- CVE-2021-26906
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 22:03 UTC · Revision 1
Source evidence
An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.
osv:ALPINE-CVE-2021-26906
asterisk
Fixed versions: 16.16.1-r0
asterisk
Fixed versions: 18.2.1-r0
asterisk
Fixed versions: 18.2.1-r0
asterisk
Fixed versions: 18.2.1-r0
asterisk
Fixed versions: 18.2.1-r0
asterisk
Fixed versions: 18.2.1-r0
asterisk
Fixed versions: 18.2.1-r0
asterisk
Fixed versions: 18.2.1-r0
asterisk
Fixed versions: 18.2.1-r0
asterisk
Fixed versions: 18.2.1-r0
asterisk
Fixed versions: 18.2.1-r0
asterisk
Fixed versions: 18.2.1-r0
asterisk
Fixed versions: 18.2.1-r0
Complete source record
{
"id": "6dc3f2655d8fdf64806ab9182a21f67a2c53c69bcc80f12b4ad761c62eea6598",
"url": "https://osv.dev/vulnerability/ALPINE-CVE-2021-26906",
"method": "structured",
"payload": {
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"title": "ALPINE-CVE-2021-26906",
"summary": "An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.",
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],
"severity": "medium",
"structured": {
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"aliases": [
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"metrics": [
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],
"modified": "2026-10-23T17:17:56.163742821Z",
"provider": "osv",
"upstream": [
"CVE-2021-26906"
],
"references": [
"https://security.alpinelinux.org/vuln/CVE-2021-26906"
]
},
"related_cves": [
{
"value": "CVE-2021-26906",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 415356,
"published_at": "2021-02-18T20:15:12.743+00:00"
}