CVE-2026-56765

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM 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: 1%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(medium)
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
1%
EPSS %ILE
41%
KEV
Not listed

Published

July 10, 2026

Last Modified

July 10, 2026

Advisory Details (2)

Auto-updated Aug 22, 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 42× in last 7d / 217× 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.

Showing the most recent 100 of 302 total refreshes for this CVE.

  1. 2026-08-28 02:39 UTCGHSA enrichment
  2. 2026-08-27 21:42 UTCEG score recompute
  3. 2026-08-27 21:42 UTCGHSA enrichment
  4. 2026-08-27 14:25 UTCEPSS rescore
  5. 2026-08-27 00:51 UTCEG score recompute
  6. 2026-08-27 00:51 UTCGHSA enrichment
  7. 2026-08-26 14:46 UTCEPSS rescore
  8. 2026-08-26 12:54 UTCGHSA enrichment
  9. 2026-08-26 08:17 UTCGHSA enrichment
  10. 2026-08-26 03:40 UTCGHSA enrichment
  11. 2026-08-25 14:44 UTCEG score recompute
  12. 2026-08-25 14:44 UTCGHSA enrichment
  13. 2026-08-25 13:49 UTCEPSS rescore
  14. 2026-08-25 09:53 UTCGHSA enrichment
  15. 2026-08-25 04:29 UTCGHSA enrichment
  16. 2026-08-25 00:23 UTCGHSA enrichment
  17. 2026-08-24 20:16 UTCEG score recompute
  18. 2026-08-24 20:16 UTCGHSA enrichment
  19. 2026-08-24 13:37 UTCGHSA enrichment
  20. 2026-08-24 09:30 UTCEG score recompute
  21. 2026-08-24 09:30 UTCGHSA enrichment
  22. 2026-08-24 03:56 UTCGHSA enrichment
  23. 2026-08-23 22:28 UTCGHSA enrichment
  24. 2026-08-23 18:21 UTCGHSA enrichment
  25. 2026-08-23 14:15 UTCGHSA enrichment
Show 75 more
  1. 2026-08-23 10:08 UTCGHSA enrichment
  2. 2026-08-23 06:01 UTCGHSA enrichment
  3. 2026-08-23 01:54 UTCEG score recompute
  4. 2026-08-23 01:54 UTCGHSA enrichment
  5. 2026-08-23 00:19 UTCEPSS rescore
  6. 2026-08-22 21:37 UTCGHSA enrichment
  7. 2026-08-22 17:30 UTCGHSA enrichment
  8. 2026-08-22 13:16 UTCGHSA enrichment
  9. 2026-08-22 09:09 UTCGHSA enrichment
  10. 2026-08-22 05:02 UTCGHSA enrichment
  11. 2026-08-22 00:56 UTCEG score recompute
  12. 2026-08-22 00:56 UTCGHSA enrichment
  13. 2026-08-21 23:49 UTCEPSS rescore
  14. 2026-08-21 20:49 UTCGHSA enrichment
  15. 2026-08-21 16:42 UTCGHSA enrichment
  16. 2026-08-21 11:58 UTCGHSA enrichment
  17. 2026-08-21 07:52 UTCGHSA enrichment
  18. 2026-08-21 03:45 UTCGHSA enrichment
  19. 2026-08-20 23:26 UTCEG score recompute
  20. 2026-08-20 23:26 UTCGHSA enrichment
  21. 2026-08-20 22:55 UTCEPSS rescore
  22. 2026-08-20 19:20 UTCGHSA enrichment
  23. 2026-08-20 15:13 UTCGHSA enrichment
  24. 2026-08-20 09:47 UTCGHSA enrichment
  25. 2026-08-20 05:41 UTCGHSA enrichment
  26. 2026-08-20 01:34 UTCEG score recompute
  27. 2026-08-20 01:34 UTCGHSA enrichment
  28. 2026-08-19 17:04 UTCEPSS rescore
  29. 2026-08-19 13:27 UTCGHSA enrichment
  30. 2026-08-19 09:16 UTCGHSA enrichment
  31. 2026-08-19 04:50 UTCGHSA enrichment
  32. 2026-08-19 00:44 UTCGHSA enrichment
  33. 2026-08-18 20:36 UTCEG score recompute
  34. 2026-08-18 20:36 UTCGHSA enrichment
  35. 2026-08-18 13:48 UTCEPSS rescore
  36. 2026-08-18 11:28 UTCGHSA enrichment
  37. 2026-08-18 07:00 UTCGHSA enrichment
  38. 2026-08-18 02:52 UTCGHSA enrichment
  39. 2026-08-17 22:12 UTCEG score recompute
  40. 2026-08-17 22:12 UTCGHSA enrichment
  41. 2026-08-17 13:47 UTCEPSS rescore
  42. 2026-08-17 13:15 UTCGHSA enrichment
  43. 2026-08-17 09:09 UTCGHSA enrichment
  44. 2026-08-17 05:03 UTCGHSA enrichment
  45. 2026-08-17 00:56 UTCGHSA enrichment
  46. 2026-08-16 20:49 UTCGHSA enrichment
  47. 2026-08-16 16:42 UTCEG score recompute
  48. 2026-08-16 16:42 UTCGHSA enrichment
  49. 2026-08-16 14:56 UTCEPSS rescore
  50. 2026-08-16 12:36 UTCGHSA enrichment
  51. 2026-08-16 08:29 UTCGHSA enrichment
  52. 2026-08-16 04:23 UTCEG score recompute
  53. 2026-08-16 04:23 UTCGHSA enrichment
  54. 2026-08-16 02:14 UTCEPSS rescore
  55. 2026-08-16 00:17 UTCGHSA enrichment
  56. 2026-08-15 20:10 UTCGHSA enrichment
  57. 2026-08-15 15:58 UTCGHSA enrichment
  58. 2026-08-15 11:51 UTCGHSA enrichment
  59. 2026-08-15 07:44 UTCGHSA enrichment
  60. 2026-08-15 02:02 UTCEG score recompute
  61. 2026-08-15 02:02 UTCGHSA enrichment
  62. 2026-08-15 01:30 UTCEPSS rescore
  63. 2026-08-14 21:56 UTCGHSA enrichment
  64. 2026-08-14 17:49 UTCGHSA enrichment
  65. 2026-08-14 13:39 UTCGHSA enrichment
  66. 2026-08-14 09:32 UTCGHSA enrichment
  67. 2026-08-14 05:26 UTCGHSA enrichment
  68. 2026-08-14 01:20 UTCEG score recompute
  69. 2026-08-14 01:20 UTCGHSA enrichment
  70. 2026-08-13 22:00 UTCEPSS rescore
  71. 2026-08-13 21:13 UTCGHSA enrichment
  72. 2026-08-13 17:01 UTCGHSA enrichment
  73. 2026-08-13 12:42 UTCGHSA enrichment
  74. 2026-08-13 08:36 UTCGHSA enrichment
  75. 2026-08-13 04:30 UTCGHSA enrichment

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 1% probability of exploitation in the next 30 days, which ranks it in the top 58.6% 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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