CVE-2026-86285

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreHIGH confidence

Score 4.3 from GitHub Security Advisory (severity: LOW) published 2026-09-07. 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.

A vulnerability was detected in BookStack up to 26.05.2. Affected by this issue is the function AttachmentController::getUpdateForm of the file app/Uploads/Controllers/AttachmentController.php of the component Attachment Edit Endpoint. The manipulation of the argument ID results in improper access controls. The attack may be launched remotely. The exploit is now public and may be used. The patch is identified as 4e406c41c4c8060a5795e74c66fb96362e54f400. It is advisable to implement a patch to correct this issue.

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
13%
KEV
Not listed

Published

September 7, 2026

Last Modified

September 9, 2026

Advisory Details (2)

Auto-updated Sep 7, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

Cookie monster!

https://codeberg.org/bookstack/bookstack/commit/4e406c41c4c8060a5795e74c66fb96362e54f400
generic🟡 PoC Available

Broken Access Control in BookStack: How a Missing Permission Check Leaked Attachment Data · Ashutosh Jena

https://ashutosh-jena.in/blog/broken-access-control-in-bookstack-how-a-missing-permission-check-leaked-attachment-data

Vendor Advisories for CVE-2026-86285(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 20× in last 7d / 46× 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 00:22 UTCEG score recompute
  2. 2026-09-20 00:22 UTCGHSA enrichment
  3. 2026-09-19 01:45 UTCEG score recompute
  4. 2026-09-19 01:45 UTCGHSA enrichment
  5. 2026-09-18 19:28 UTCEPSS rescore
  6. 2026-09-18 03:08 UTCEG score recompute
  7. 2026-09-18 03:08 UTCGHSA enrichment
  8. 2026-09-17 19:32 UTCEPSS rescore
  9. 2026-09-17 04:31 UTCEG score recompute
  10. 2026-09-17 04:31 UTCGHSA enrichment
  11. 2026-09-16 14:09 UTCEPSS rescore
  12. 2026-09-16 05:54 UTCEG score recompute
  13. 2026-09-16 05:54 UTCGHSA enrichment
  14. 2026-09-16 05:15 UTCEPSS rescore
  15. 2026-09-15 07:17 UTCEG score recompute
  16. 2026-09-15 07:17 UTCGHSA enrichment
  17. 2026-09-15 03:12 UTCEPSS rescore
  18. 2026-09-15 03:12 UTCEPSS rescore
  19. 2026-09-14 08:39 UTCEG score recompute
  20. 2026-09-14 08:39 UTCGHSA enrichment
  21. 2026-09-13 10:02 UTCEG score recompute
  22. 2026-09-13 10:02 UTCGHSA enrichment
  23. 2026-09-12 11:25 UTCEG score recompute
  24. 2026-09-12 11:25 UTCGHSA enrichment
  25. 2026-09-11 14:53 UTCEPSS rescore
Show 21 more
  1. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-11 12:48 UTCEG score recompute
  3. 2026-09-11 12:47 UTCGHSA enrichment
  4. 2026-09-10 14:09 UTCEG score recompute
  5. 2026-09-10 14:09 UTCGHSA enrichment
  6. 2026-09-09 15:31 UTCEG score recompute
  7. 2026-09-09 15:31 UTCGHSA enrichment
  8. 2026-09-09 15:26 UTCNVD updateCVSS v4 → 2.1
  9. 2026-09-09 14:37 UTCEG score recompute
  10. 2026-09-09 14:37 UTCGHSA enrichment
  11. 2026-09-09 14:34 UTCMITRE cvelistV5CVSS v4 → 5.3
  12. 2026-09-09 12:42 UTCEG score recompute
  13. 2026-09-09 12:42 UTCGHSA enrichment
  14. 2026-09-08 22:01 UTCEPSS rescore
  15. 2026-09-08 13:56 UTCGHSA enrichment
  16. 2026-09-08 08:11 UTCEG score recompute
  17. 2026-09-08 08:11 UTCGHSA enrichment
  18. 2026-09-07 09:30 UTCEG score recompute
  19. 2026-09-07 09:30 UTCNVD updateCVSS v4 → 2.1
  20. 2026-09-07 08:38 UTCEG score recompute
  21. 2026-09-07 08:36 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-86285?
CVE-2026-86285 is a medium vulnerability published on September 7, 2026. A vulnerability was detected in BookStack up to 26.05.2. Affected by this issue is the function AttachmentController::getUpdateForm of the file app/Uploads/Controllers/AttachmentController.php of the component Attachment Edit Endpoint. The manipulation of the argument ID results in improper access…
When was CVE-2026-86285 disclosed?
CVE-2026-86285 was first published in the National Vulnerability Database on September 7, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-86285 actively exploited?
CVE-2026-86285 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 87.0% of all scored CVEs.
What is the CVSS score of CVE-2026-86285?
CVE-2026-86285 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-86285?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-86285, 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

Explore the affected products and dependency analysis for CVE-2026-86285

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