What is CVE-2021-43611?

CVE-2021-43611 is a high-severity vulnerability in Linphone Belle-Sip, classified under Improper Resource Shutdown or Release. CVSS score: 7.5/10. Published 2021-11-12.

How severe is CVE-2021-43611?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Linphone Belle-Sip

CVE-2021-43611

Belledonne Belle-sip before 5.0.20 can crash applications such as Linphone via " \ " in the display name of a From header.

Published 2021-11-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.012 (67.4th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 67.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: +0.000

Affected products

Linphone Belle-Sip

Weakness classification (CWE)

CWE-404 — Improper Resource Shutdown or Release

References

github.com/BelledonneCommunications/belle-sip/commit/d3f0651531e45e91c2e60f3a16… (Patch, Third Party Advisory)
github.com/BelledonneCommunications/belle-sip/compare/5.0.18...5.0.20 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-43611?: CVE-2021-43611 is a high-severity vulnerability in Linphone Belle-Sip, classified under Improper Resource Shutdown or Release. CVSS score: 7.5/10. Published 2021-11-12.
How severe is CVE-2021-43611?: High severity. CVSS v3 base score is 7.5 out of 10.