CVE-2026-56765

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-10. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.8Exploit: NoneExposed: 0

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

Vikunja before 2.2.1 contains an authorization flaw where the LinkSharing.ReadAll endpoint exposes share hashes to users with read access, enabling permission escalation to admin-level shares. The GetTaskAttachment endpoint performs permission checks against user-supplied task IDs but fetches attachments by sequential ID without verifying ownership, allowing attackers to download and delete all file attachments across all projects instance-wide.

CVSS v3
9.8
EG Score
9.8(high)
EPSS
27.5%
KEV
Not listed

Published

July 10, 2026

Last Modified

July 10, 2026

Advisory Details (2)

Auto-updated Jul 18, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Unauthenticated Instance-Wide Data Breach via Link Share Hash Disclosure Chained with Cross-Project Attachment IDOR · Advisory · go-vikunja/vikunja · GitHub

https://github.com/go-vikunja/vikunja/security/advisories/GHSA-2pv8-4c52-mf8j
generic

Vikunja - Unauthenticated Instance-Wide Data Breach via Link Share Hash Disclosure Chained with Cross-Project Attachment IDOR | Advisories | VulnCheck

https://www.vulncheck.com/advisories/vikunja-unauthenticated-instance-wide-data-breach-via-link-share-hash-disclosure-chained-with-cross-project-attachment-idor

Vendor Advisories for CVE-2026-56765(1)

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

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
code.vikunja.io/api—2.2.1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 56× 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. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:25 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:31 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 02:29 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-17 03:11 UTCGHSA enrichment
  9. 2026-07-16 23:05 UTCGHSA enrichment
  10. 2026-07-16 18:59 UTCGHSA enrichment
  11. 2026-07-16 17:03 UTCEPSS rescore
  12. 2026-07-16 14:52 UTCGHSA enrichment
  13. 2026-07-16 10:44 UTCGHSA enrichment
  14. 2026-07-16 06:38 UTCGHSA enrichment
  15. 2026-07-16 02:30 UTCGHSA enrichment
  16. 2026-07-15 22:24 UTCGHSA enrichment
  17. 2026-07-15 18:18 UTCGHSA enrichment
  18. 2026-07-15 16:57 UTCEPSS rescore
  19. 2026-07-15 16:57 UTCEPSS rescore
  20. 2026-07-15 14:11 UTCGHSA enrichment
  21. 2026-07-15 10:04 UTCGHSA enrichment
  22. 2026-07-15 05:57 UTCGHSA enrichment
  23. 2026-07-15 02:00 UTCEPSS rescore
  24. 2026-07-15 02:00 UTCEPSS rescore
  25. 2026-07-15 01:43 UTCGHSA enrichment
Show 31 more
  1. 2026-07-14 21:36 UTCGHSA enrichment
  2. 2026-07-14 17:29 UTCGHSA enrichment
  3. 2026-07-14 13:23 UTCGHSA enrichment
  4. 2026-07-14 09:16 UTCGHSA enrichment
  5. 2026-07-14 05:09 UTCGHSA enrichment
  6. 2026-07-14 01:00 UTCGHSA enrichment
  7. 2026-07-13 22:31 UTCEPSS rescore
  8. 2026-07-13 20:54 UTCGHSA enrichment
  9. 2026-07-13 16:47 UTCGHSA enrichment
  10. 2026-07-13 12:40 UTCGHSA enrichment
  11. 2026-07-13 08:33 UTCGHSA enrichment
  12. 2026-07-13 06:13 UTCEPSS rescore
  13. 2026-07-13 06:13 UTCEPSS rescore
  14. 2026-07-13 04:24 UTCGHSA enrichment
  15. 2026-07-13 00:17 UTCGHSA enrichment
  16. 2026-07-12 20:11 UTCGHSA enrichment
  17. 2026-07-12 16:04 UTCGHSA enrichment
  18. 2026-07-12 11:57 UTCGHSA enrichment
  19. 2026-07-12 07:51 UTCGHSA enrichment
  20. 2026-07-12 05:46 UTCEPSS rescore
  21. 2026-07-12 03:44 UTCGHSA enrichment
  22. 2026-07-11 23:37 UTCGHSA enrichment
  23. 2026-07-11 19:30 UTCGHSA enrichment
  24. 2026-07-11 15:23 UTCGHSA enrichment
  25. 2026-07-11 11:16 UTCGHSA enrichment
  26. 2026-07-11 07:10 UTCGHSA enrichment
  27. 2026-07-11 03:03 UTCGHSA enrichment
  28. 2026-07-10 22:55 UTCGHSA enrichment
  29. 2026-07-10 18:49 UTCGHSA enrichment
  30. 2026-07-10 14:43 UTCEG score recompute
  31. 2026-07-10 14:42 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-56765?
CVE-2026-56765 is a critical vulnerability published on July 10, 2026. Vikunja before 2.2.1 contains an authorization flaw where the LinkSharing.ReadAll endpoint exposes share hashes to users with read access, enabling permission escalation to admin-level shares. The GetTaskAttachment endpoint performs permission checks against user-supplied task IDs but fetches…
When was CVE-2026-56765 disclosed?
CVE-2026-56765 was first published in the National Vulnerability Database on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56765 actively exploited?
CVE-2026-56765 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 27.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56765?
CVE-2026-56765 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-56765?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56765, 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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