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
Trending — 3 sources updated this weekElevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: Elevated riskExposed: 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)
EG Risk
75(Attend)
EG Risk 75/100SSVC: Attend

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
Severity98% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
28%
KEV
Not listed

Published

July 10, 2026

Last Modified

July 10, 2026

Advisory Details (2)

Auto-updated Jul 25, 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———

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 31× in last 7d / 86× 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. 2026-07-29 06:54 UTCGHSA enrichment
  2. 2026-07-29 02:42 UTCGHSA enrichment
  3. 2026-07-28 22:34 UTCGHSA enrichment
  4. 2026-07-28 18:24 UTCEG score recompute
  5. 2026-07-28 18:24 UTCGHSA enrichment
  6. 2026-07-28 15:37 UTCEPSS rescore
  7. 2026-07-28 14:18 UTCGHSA enrichment
  8. 2026-07-28 10:07 UTCGHSA enrichment
  9. 2026-07-28 06:01 UTCGHSA enrichment
  10. 2026-07-28 01:52 UTCGHSA enrichment
  11. 2026-07-27 21:45 UTCGHSA enrichment
  12. 2026-07-27 17:25 UTCEG score recompute
  13. 2026-07-27 17:25 UTCGHSA enrichment
  14. 2026-07-27 14:14 UTCEPSS rescore
  15. 2026-07-27 13:19 UTCGHSA enrichment
  16. 2026-07-27 09:12 UTCGHSA enrichment
  17. 2026-07-27 05:05 UTCGHSA enrichment
  18. 2026-07-27 00:37 UTCGHSA enrichment
  19. 2026-07-26 20:26 UTCGHSA enrichment
  20. 2026-07-26 16:20 UTCEG score recompute
  21. 2026-07-26 16:19 UTCGHSA enrichment
  22. 2026-07-26 14:54 UTCEPSS rescore
  23. 2026-07-26 14:54 UTCEPSS rescore
  24. 2026-07-26 12:12 UTCEG score recompute
  25. 2026-07-26 12:12 UTCGHSA enrichment
Show 61 more
  1. 2026-07-25 14:18 UTCEPSS rescore
  2. 2026-07-25 14:18 UTCEPSS rescore
  3. 2026-07-24 14:18 UTCEPSS rescore
  4. 2026-07-23 14:18 UTCEPSS rescore
  5. 2026-07-23 03:20 UTCEG score recompute
  6. 2026-07-22 14:08 UTCEPSS rescore
  7. 2026-07-21 15:25 UTCEPSS rescore
  8. 2026-07-20 17:08 UTCEPSS rescore
  9. 2026-07-19 14:31 UTCEPSS rescore
  10. 2026-07-19 14:31 UTCEPSS rescore
  11. 2026-07-19 02:29 UTCEPSS rescore
  12. 2026-07-18 10:04 UTCEPSS rescore
  13. 2026-07-17 03:11 UTCGHSA enrichment
  14. 2026-07-16 23:05 UTCGHSA enrichment
  15. 2026-07-16 18:59 UTCGHSA enrichment
  16. 2026-07-16 17:03 UTCEPSS rescore
  17. 2026-07-16 14:52 UTCGHSA enrichment
  18. 2026-07-16 10:44 UTCGHSA enrichment
  19. 2026-07-16 06:38 UTCGHSA enrichment
  20. 2026-07-16 02:30 UTCGHSA enrichment
  21. 2026-07-15 22:24 UTCGHSA enrichment
  22. 2026-07-15 18:18 UTCGHSA enrichment
  23. 2026-07-15 16:57 UTCEPSS rescore
  24. 2026-07-15 16:57 UTCEPSS rescore
  25. 2026-07-15 14:11 UTCGHSA enrichment
  26. 2026-07-15 10:04 UTCGHSA enrichment
  27. 2026-07-15 05:57 UTCGHSA enrichment
  28. 2026-07-15 02:00 UTCEPSS rescore
  29. 2026-07-15 02:00 UTCEPSS rescore
  30. 2026-07-15 01:43 UTCGHSA enrichment
  31. 2026-07-14 21:36 UTCGHSA enrichment
  32. 2026-07-14 17:29 UTCGHSA enrichment
  33. 2026-07-14 13:23 UTCGHSA enrichment
  34. 2026-07-14 09:16 UTCGHSA enrichment
  35. 2026-07-14 05:09 UTCGHSA enrichment
  36. 2026-07-14 01:00 UTCGHSA enrichment
  37. 2026-07-13 22:31 UTCEPSS rescore
  38. 2026-07-13 20:54 UTCGHSA enrichment
  39. 2026-07-13 16:47 UTCGHSA enrichment
  40. 2026-07-13 12:40 UTCGHSA enrichment
  41. 2026-07-13 08:33 UTCGHSA enrichment
  42. 2026-07-13 06:13 UTCEPSS rescore
  43. 2026-07-13 06:13 UTCEPSS rescore
  44. 2026-07-13 04:24 UTCGHSA enrichment
  45. 2026-07-13 00:17 UTCGHSA enrichment
  46. 2026-07-12 20:11 UTCGHSA enrichment
  47. 2026-07-12 16:04 UTCGHSA enrichment
  48. 2026-07-12 11:57 UTCGHSA enrichment
  49. 2026-07-12 07:51 UTCGHSA enrichment
  50. 2026-07-12 05:46 UTCEPSS rescore
  51. 2026-07-12 03:44 UTCGHSA enrichment
  52. 2026-07-11 23:37 UTCGHSA enrichment
  53. 2026-07-11 19:30 UTCGHSA enrichment
  54. 2026-07-11 15:23 UTCGHSA enrichment
  55. 2026-07-11 11:16 UTCGHSA enrichment
  56. 2026-07-11 07:10 UTCGHSA enrichment
  57. 2026-07-11 03:03 UTCGHSA enrichment
  58. 2026-07-10 22:55 UTCGHSA enrichment
  59. 2026-07-10 18:49 UTCGHSA enrichment
  60. 2026-07-10 14:43 UTCEG score recompute
  61. 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 0% probability of exploitation in the next 30 days, which ranks it in the top 71.6% of all scored CVEs.
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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