CVE-2021-39923

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-11-19 · updated 2026-06-17
Weakness: CWE-834

Description

Large loop in the PNRP dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Affected products

Debian Linux: 10.0, 11.0, 9.0
Wireshark Foundation Wireshark: from 3.2.0 through 3.2.17; from 3.4.0 through 3.4.9

References

https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39923.json
https://gitlab.com/wireshark/wireshark/-/issues/17684
https://lists.debian.org/debian-lts-announce/2021/12/msg00015.html
https://www.debian.org/security/2021/dsa-5019
https://www.wireshark.org/security/wnpa-sec-2021-11.html
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39923.json
https://gitlab.com/wireshark/wireshark/-/issues/17684
https://lists.debian.org/debian-lts-announce/2021/12/msg00015.html
https://www.debian.org/security/2021/dsa-5019
https://www.wireshark.org/security/wnpa-sec-2021-11.html

Get alerted when CVE-2021-39923 or the next vulnerability affects your stack