CVE-2026-91984

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 — 4 sources updated this week
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: None knownExposed: 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 that user-supplied project_view_id in task-position requests belongs to the task's project. Authenticated attackers can insert task position rows into arbitrary other tenant project views via POST or PUT task-position endpoints.

CVSS v3
4.3
EG Score
4.3(high)
EG Risk
19(Track)
EG Risk 19/100SSVC: 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%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
11%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 17, 2026

Advisory Details (2)

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

Vikunja before 2.6.0 Broken Object-Level Authorization via task-position | Advisories | VulnCheck

https://www.vulncheck.com/advisories/vikunja-before-2.6.0-broken-object-level-authorization-via-task-position
github Patch Available🟡 PoC Available

Cross-tenant task-position rows can be injected into arbitrary project views via the unvalidated project_view_id in the task position endpoint (v1 and v2) · Advisory · go-vikunja/vikunja · GitHub

https://github.com/go-vikunja/vikunja/security/advisories/GHSA-w39f-h553-h2mx

Vendor Advisories for CVE-2026-91984(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 20× in last 7d / 20× 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. 2026-09-20 23:23 UTCEG score recompute
  2. 2026-09-20 23:23 UTCGHSA enrichment
  3. 2026-09-20 20:16 UTCEPSS rescore
  4. 2026-09-19 22:24 UTCEG score recompute
  5. 2026-09-19 22:24 UTCGHSA enrichment
  6. 2026-09-18 21:26 UTCEG score recompute
  7. 2026-09-18 21:26 UTCGHSA enrichment
  8. 2026-09-18 19:28 UTCEPSS rescore
  9. 2026-09-17 20:29 UTCEG score recompute
  10. 2026-09-17 20:29 UTCGHSA enrichment
  11. 2026-09-17 19:39 UTCEG score recompute
  12. 2026-09-17 19:39 UTCGHSA enrichment
  13. 2026-09-17 19:32 UTCEPSS rescore
  14. 2026-09-16 21:07 UTCGHSA enrichment
  15. 2026-09-16 17:55 UTCEG score recompute
  16. 2026-09-16 17:55 UTCGHSA enrichment
  17. 2026-09-16 14:09 UTCEPSS rescore
  18. 2026-09-15 16:32 UTCEG score recompute
  19. 2026-09-15 15:23 UTCEG score recompute
  20. 2026-09-15 15:22 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-91984?
CVE-2026-91984 is a medium vulnerability published on September 15, 2026. Vikunja before 2.6.0 fails to validate that user-supplied projectviewid in task-position requests belongs to the task's project. Authenticated attackers can insert task position rows into arbitrary other tenant project views via POST or PUT task-position endpoints.
When was CVE-2026-91984 disclosed?
CVE-2026-91984 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-91984 actively exploited?
CVE-2026-91984 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 88.8% of all scored CVEs.
What is the CVSS score of CVE-2026-91984?
CVE-2026-91984 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-91984?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-91984, 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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