vulnerability / NVI-00005107 / Revision 4
Remote Code Execution Through Image Uploads in BookStack
OSV carries this publisher advisory for ssddanbrown/bookstack. This is an aggregated source copy; consult the original publisher and compare update dates.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
9 HIGH (2.0)
nvd@nist.gov severity; no combined Null risk score.
7.9 HIGH (3.1)
security-advisories@github.com severity; no combined Null risk score.
8.8 HIGH (3.1)
nvd@nist.gov severity; no combined Null risk score.
1.969%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.804. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
ssddanbrown/bookstack
source listedECOSYSTEM: introduced 0; fixed 0.25.5
### Impact A user could upload PHP files through image upload functions, which would allow them to execute code on the host system remotely. They would then have the permissions of the PHP process. This most impacts scenarios where non-trusted users are given permission to upload images in any area of the application. ### Patches The issue was addressed in a series of patches: v0.25.3, v0.25.4 and v0.25.5. Users should upgrade to at least v0.25.5 to avoid this patch but ideally the latest BookStack version as previous versions are un-supported. ### Workarounds Depending on BookStack version, you could use the local_secure image storage option, or use s3 or a similar compatible service. Preventing direct execution of any `php` files, apart from the `public/index.php` file, though web-server configuration would also prevent this. ### References BookStack Beta v0.25.3 BookStack Beta v0.25.4 [BookStack Beta v0.25.5](https://github.com/BookStackApp/BookStack/releases/tag/v0.25.
03 / Response
What to do next
- vendor patch
The original advisory lists fixed boundaries 0.25.5 for ssddanbrown/bookstack. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-g9rq-x4fj-f5hx ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2020-5256 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
- CVE-2020-5256 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 4 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 3 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.