A vulnerability was detected in grimmory-tools grimmory up to 3.3.3/3.4.1. Affected by this vulnerability is the function streamFileToResponse of the file backend/src/main/java/org/booklore/controller/KoboController.java of the component Download Endpoint. Performing a manipulation of the argument bookId results in authorization bypass. The attack may be initiated remotely. The exploit is now public and may be used. Issue #2431 is closed as completed, but its only comment states that the issue “has already been reported elsewhere.” No fixing commit or pull request is identified there.
CVE-2026-93955
This medium-severity CVE scores 4.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 4.3
- EG Score
- 4.3(low)
- EG Risk
- 24(Track)EG Risk 24/100SSVC: 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 computedSeverity43% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 34%
- KEV
- Not listed
Published
September 19, 2026
Last Modified
September 19, 2026
Advisory Details (3)
Auto-updated Sep 19, 2026GitHub - grimmory-tools/grimmory: A self-hosted library for your ebooks, comics, and audiobooks · GitHub
https://github.com/grimmory-tools/grimmory/Kobo download endpoint lacks library access control (CWE-639) · Issue #2431 · grimmory-tools/grimmory · GitHub
https://github.com/grimmory-tools/grimmory/issues/2431#issuecomment-5384402858Kobo download endpoint lacks library access control (CWE-639) · Issue #2431 · grimmory-tools/grimmory · GitHub
https://github.com/grimmory-tools/grimmory/issues/2431Vendor Advisories for CVE-2026-93955(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 5× in last 7d / 5× 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.
- 2026-09-20 20:16 UTCEPSS rescore
- 2026-09-19 23:27 UTCEG score recompute
- 2026-09-19 23:27 UTCNVD updateCVSS v4 → 2.1
- 2026-09-19 22:21 UTCEG score recompute
- 2026-09-19 22:20 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
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Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-93955
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