CVE-2026-91980

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreHIGH confidence

Score 4.3 from GitHub Security Advisory published 2026-09-15. a secondary CVSS source baseline 4.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.3Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

vikunja before 2.6.0 fails to validate team access when attaching teams to projects, allowing authenticated users to enumerate all teams and members. Attackers can attach arbitrary team IDs via the project teams endpoint to retrieve complete team rosters including member names and admin flags for unauthorized teams.

CVSS v3
4.3
EG Score
4.3(high)
EG Risk
35(Track)
EG Risk 35/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity43% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
21%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 16, 2026

Advisory Details (2)

Auto-updated Sep 15, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

vikunja before 2.6.0 Team Enumeration via Project Share | Advisories | VulnCheck

https://www.vulncheck.com/advisories/vikunja-before-2.6.0-team-enumeration-via-project-share
github Patch Available🟡 PoC Available

Any user can enumerate every team and its members by attaching arbitrary teams to a throwaway project · Advisory · go-vikunja/vikunja · GitHub

https://github.com/go-vikunja/vikunja/security/advisories/GHSA-39p5-2wrr-xh29

Vendor Advisories for CVE-2026-91980(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 21× in last 7d / 31× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-09-25 08:24 UTCEG score recompute
  2. 2026-09-25 08:24 UTCGHSA enrichment
  3. 2026-09-24 14:04 UTCEPSS rescore
  4. 2026-09-24 09:47 UTCEG score recompute
  5. 2026-09-24 09:47 UTCGHSA enrichment
  6. 2026-09-23 17:54 UTCEPSS rescore
  7. 2026-09-23 11:10 UTCEG score recompute
  8. 2026-09-23 11:10 UTCGHSA enrichment
  9. 2026-09-22 16:01 UTCEPSS rescore
  10. 2026-09-22 12:32 UTCEG score recompute
  11. 2026-09-22 12:32 UTCGHSA enrichment
  12. 2026-09-21 21:09 UTCEPSS rescore
  13. 2026-09-21 13:55 UTCEG score recompute
  14. 2026-09-21 13:55 UTCGHSA enrichment
  15. 2026-09-20 20:16 UTCEPSS rescore
  16. 2026-09-20 15:17 UTCGHSA enrichment
  17. 2026-09-19 16:36 UTCEG score recompute
  18. 2026-09-19 16:36 UTCGHSA enrichment
  19. 2026-09-18 19:28 UTCEPSS rescore
  20. 2026-09-18 17:59 UTCEG score recompute
  21. 2026-09-18 17:59 UTCGHSA enrichment
  22. 2026-09-17 19:32 UTCEPSS rescore
  23. 2026-09-17 19:22 UTCGHSA enrichment
  24. 2026-09-16 19:57 UTCGHSA enrichment
  25. 2026-09-16 16:09 UTCEG score recompute
Show 6 more
  1. 2026-09-16 16:09 UTCGHSA enrichment
  2. 2026-09-16 14:09 UTCEPSS rescore
  3. 2026-09-15 17:32 UTCEG score recompute
  4. 2026-09-15 16:18 UTCEG score recompute
  5. 2026-09-15 15:23 UTCEG score recompute
  6. 2026-09-15 15:22 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-91980?
CVE-2026-91980 is a medium vulnerability published on September 15, 2026. vikunja before 2.6.0 fails to validate team access when attaching teams to projects, allowing authenticated users to enumerate all teams and members. Attackers can attach arbitrary team IDs via the project teams endpoint to retrieve complete team rosters including member names and admin flags for…
When was CVE-2026-91980 disclosed?
CVE-2026-91980 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-91980 actively exploited?
CVE-2026-91980 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 79.2% of all scored CVEs.
What is the CVSS score of CVE-2026-91980?
CVE-2026-91980 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-91980?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-91980, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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