Improper Access Control in zulip/zulip

published 2022-02-26 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-27172

cvss: 4.1; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 58%
public exploits: 0; none known

Improper Access Control in GitHub repository zulip/zulip prior to 4.10.

Patch / fix

fixed in 1 links 1

zulip zulip/zulip 4.10

github.com/zulip/zulip@d5db254 commit

Exploit prediction

0.84% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

huntr.dev https://huntr.dev/bounties/2928a625-0467-4a0a-b4e2-e27322786686 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.0	4.1	CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L
NVD	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	6.5	AV:N/AC:L/Au:S/C:P/I:P/A:P

Affected products

zulip zulip/zulip

Classification

Weakness

CWE-284 Improper Access Control

References

github.com /zulip/zulip/commit/d5db254ca8167995a1654d1c45ffc74b2fade39a
patch, third-party-advisory
huntr.dev /bounties/2928a625-0467-4a0a-b4e2-e27322786686
exploit, third-party-advisory

Sources

CVE List CVE-2021-3967
NVD CVE-2021-3967

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary