CVE-2021-26713

mediumpriority · track · 27EPSS 0.019 · 79 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.87% (79th) EPSS

CVSS 4 · medium

Is it mine?

5 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-28

A stack-based buffer overflow in res_rtp_asterisk.c in Sangoma Asterisk before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6 allows an authenticated WebRTC client to cause an Asterisk crash by sending multiple hold/unhold requests in quick succession. This is caused by a signedness comparison mismatch.

cvss

Technical severity, 0–10. One row per scoring source.

6.5

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04mediumAV:N/AC:L/Au:S/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8 · impact 2.9

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 3.6

v3.16mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-787USprimary

affected products (5)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
digium asterisk16.0.0 → 16.16.1nvdUScpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
digium asterisk17.0.0 → 17.9.2nvdUScpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
digium asterisk18.0.0 → 18.2.1nvdUScpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
digium certified asterisk= 16.8nvdUScpe:2.3:a:digium:certified_asterisk:*:*:*:*:*:*:*:*

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2021-02-19modified 2026-06-17

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+16132 more

references (10)

External citations — patches, advisories, analysis.

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