CVE-2026-1268115.4MediumCWE-863

CVE-2026-126811: BookStack before 26.09.3 Incorrect Authorization via Image and Drawio Endpoints

BookStackApp · BookStack

Fixed in 26.09.3 · Affected: BookStackApp before 26.09.3 · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.3%probability of exploitation in the next 30 days

21st percentile

050100

Higher than 21% of scored CVEs

5.4MediumCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

BookStack before 26.09.3 contains an incorrect authorization vulnerability that allows authenticated users to access other users' unpublished draft page images by checking only PageView permission without draft status. Attackers can read drawio data via the base64 endpoint or rename, replace, or delete draft images by sequential ID to disclose or tamper with unpublished work.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

BookStackApp · BookStackbefore 26.09.3

On the Atlas

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Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Incorrect Authorization · Access Control
Vendor: BookStackApp
Published: November 2026
Band: Unlikely (under 1%), November 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-126811 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.