Secure-upload disclosure via unauthorized hotlink copying
Published Jul 9, 2026 · Updated Jul 9, 2026
Information disclosure in affected Discourse 2026 branches allows remote attackers to read secure uploads through hotlinked images. Jobs::PullHotlinkedImages resolved a known presigned secure-upload URL and attached a fresh local copy to the attacker's post without checking whether its author could view the upload's access-control post. Exploitation requires secure_uploads to be enabled, knowledge of the protected URL, and permission to create a post; it exposes copied media without altering source content.
Summary
What happened
Information disclosure in affected Discourse 2026 branches allows remote attackers to read secure uploads through hotlinked images. Jobs::PullHotlinkedImages resolved a known presigned secure-upload URL and attached a fresh local copy to the attacker's post without checking whether its author could view the upload's access-control post. Exploitation requires secure_uploads to be enabled, knowledge of the protected URL, and permission to create a post; it exposes copied media without altering source content.
The record
- CVE
- CVE-2026-45788
- Published
- Jul 9, 2026
- Updated
- Jul 9, 2026
- Vendor
- Discourse
- Product
- Discourse
- Classifications
- CWE-200, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 9, 2026CVE publishedPublication date reported by the CVE source.
- Jul 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 2026.1.0-latest, < 2026.1.5
- Affected versionversion=>= 2026.4.0-latest, < 2026.4.2
- Affected versionversion=>= 2026.5.0-latest, < 2026.5.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo