Zulip is an open-source team collaboration tool with topic-based threading. Zulip Server version 2.0.0 and above are vulnerable to insufficient access control with multi-use invitations. A Zulip Server deployment which hosts multiple organizations is vulnerable to an attack where an invitation created in one organization (potentially as a role with elevated permissions) can be used to join any other organization. This bypasses any restrictions on required domains on users' email addresses, may be used to gain access to organizations which are only accessible by invitation, and may be used to gain access with elevated privileges. This issue has been patched in release 4.10. There are no known workarounds for this issue. ### Patches _Has the problem been patched? What versions should users upgrade to?_ ### Workarounds _Is there a way for users to fix or remediate the vulnerability without upgrading?_ ### References _Are there any links users can visit to find out more?_ ### For more information If you have any questions or comments about this advisory, you can discuss them on the developer community Zulip server, or email the Zulip security team.
CVE-2022-21706
“—” beside the score: it is equal to NVD's CVSS score.
This high-severity CVE scores 7.2 under NVD CVSS v3. EPSS exploit probability: 1.2% (68th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2022-26895 (ENISA EUVD)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
The CVE record names the fixed release — apply it.
- CVSS v3
- 7.2
- EG Score
- 7.2HIGHmedium confidence
- EG Risk
- 48EG Risk 48/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity72% × 45%Impact severity (EG Severity): CVSS 7.2 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation1.2% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: The CVE record names the fixed release. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 1.2%
- EPSS %ILE
- 68th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.2): severity, escalated by confirmed exploitation. This CVE's 7.2 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.2 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- 1.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-28). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
The CVE record names the fixed release. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
February 26, 2022
Last Modified
November 21, 2024
References (4)
- security-advisories@github · CVE Programhttps://blog.zulip.com/2022/02/25/zulip-cloud-invitation-vulnerability/Vendor Advisory
- security-advisories@github · CVE Programhttps://blog.zulip.com/2022/02/25/zulip-server-4-10-security-release/#cve-2022-21706Vendor Advisory
- security-advisories@github · CVE Programhttps://github.com/zulip/zulip/commit/88917019f03860609114082cdc0f31a561503f9ePatch · Third Party Advisory
- security-advisories@github · CVE Programhttps://github.com/zulip/zulip/security/advisories/GHSA-6xmj-2wcm-p2jcThird Party Advisory
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 37× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 97 of 200 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 3 repeat rows among the latest 100 are merged into the row they repeat. The 103 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-01 16:30 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-31 16:29 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-30 16:30 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-29 16:29 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-29 01:09 UTCEG score recompute
- 2026-10-28 16:28 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-27 16:28 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-26 16:28 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-25 18:15 UTCEG score recompute
- 2026-10-25 16:29 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-24 16:29 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-23 16:28 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-22 16:30 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-21 16:28 UTCEPSS rescoreEPSS 1.2% · 68th percentile
- 2026-10-21 08:06 UTCEG score recompute
- 2026-10-20 16:29 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-19 16:28 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-18 16:28 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-18 08:44 UTCEG score recompute
- 2026-10-17 16:29 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-17 03:25 UTCOSV refresh
- 2026-10-16 16:34 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-15 16:28 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-14 16:29 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-13 16:29 UTCEPSS rescoreEPSS 1.2% · 67th percentile
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- 2026-10-12 19:01 UTCEG score recompute
- 2026-10-12 16:30 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-11 23:27 UTCEG score recompute
- 2026-10-11 13:44 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-10 19:56 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-09 20:04 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-08 16:40 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-07 23:45 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-06 15:14 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-05 17:40 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-04 23:19 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-10-03 14:22 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-09-30 15:48 UTCEG score recompute
- 2026-09-30 15:00 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-09-29 15:15 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-09-28 13:48 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-09-27 13:41 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-09-26 00:22 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-09-25 04:24 UTCOSV refresh
- 2026-09-24 14:00 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-23 13:45 UTCEPSS rescoreEPSS 1.2% · 67th percentile
- 2026-09-20 20:13 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-17 19:23 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-16 14:05 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-15 03:06 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-13 16:43 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-12 14:57 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-11 14:49 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-11 09:33 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-08 21:57 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-07 15:58 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-06 13:45 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-05 20:00 UTCOSV refresh
- 2026-09-05 15:25 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-09-04 13:57 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-04 05:04 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-02 14:09 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-09-01 13:51 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-08-30 19:14 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-08-30 01:19 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-28 21:38 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-27 14:22 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-08-26 14:43 UTCEPSS rescoreEPSS 1.2% · 66th percentile
- 2026-08-25 13:46 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-24 14:13 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-21 23:46 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-20 22:52 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-19 17:01 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-19 07:02 UTCOSV refresh
- 2026-08-18 13:45 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-17 13:44 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-16 14:53 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-16 02:11 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-15 01:27 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-13 21:57 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-12 13:48 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-09 13:44 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-08 16:34 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-07 16:24 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-06 13:44 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-05 19:15 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-04 10:34 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-04 02:57 UTCOSV refresh
- 2026-08-03 10:33 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-02 02:24 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-08-01 04:13 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-07-30 16:25 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-07-30 01:28 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-07-28 15:33 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-07-26 14:52 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-07-25 14:15 UTCEPSS rescoreEPSS 1.2% · 65th percentile
- 2026-07-24 14:15 UTCEPSS rescoreEPSS 1.4% · 69th percentile
Related CVEs(same CWE)
Same CWE
10 shownCWE-863 · CWE-284
Frequently asked(5)
What is CVE-2022-21706?
When was the CVE record for CVE-2022-21706 published?
Is CVE-2022-21706 actively exploited?
What is the CVSS score of CVE-2022-21706?
How do I remediate CVE-2022-21706?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2022-21706
Is Your Infrastructure Affected by CVE-2022-21706?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.