Unbounded unauthenticated uploads in ApostropheCMS Form exhaust disk
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-770.
Summary
ApostropheCMS Form add-on (@apostrophecms/form) before 1.5.5 stages multipart uploads in its form submission route before validation or authentication. The route has no upload size, count or rate limits (CWE-770). An unauthenticated remote attacker can repeat submissions to consume temporary disk storage, disrupting form handling and other host services.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
ApostropheCMS is an open-source Node.js content management system. Prior to 1.5.5 of the ApostropheCMS Form add-on, its form submission route stages unbounded multipart uploads before form validation or authentication and lacks upload size, count, and rate limits. Repeated unauthenticated submissions can consume temporary disk storage and disrupt form handling or other host services. This issue is fixed in ApostropheCMS Form 1.5.5.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| apostrophecms | apostrophe | before 4.33.0 | 4.33.0 | Patch available | CNA |
| apostrophecms | form | before 1.5.5 | 1.5.5 | Patch available | CNA |
| — | @apostrophecms/form (npm) | before 1.5.5 | 1.5.5 | Patch available | GHSA-89mh-mm8c-mv7f |
- apostrophe Vendorapostrophecms Affected before 4.33.0 Fixed in 4.33.0 Patch available CNA
- form Vendorapostrophecms Affected before 1.5.5 Fixed in 1.5.5 Patch available CNA
- @apostrophecms/form (npm) Vendor— Affected before 1.5.5 Fixed in 1.5.5 Patch available GHSA-89mh-mm8c-mv7f
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:apostrophecms:apostrophecms:*:*:*:*:*:*:*:* | — | — | apostrophecms |
- cpe:2.3:a:apostrophecms:apostrophecms:*:*:*:*:*:*:*:* Versions — — ·apostrophecms
Remediation
Update @apostrophecms/form to 1.5.5, the fixed version. The apostrophe package (before 4.33.0) is listed as affected, with no fix listed.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA apostrophe (apostrophecms) Fixed in 4.33.0
- Fix · CNA form (@apostrophecms) Fixed in 1.5.5
- Fix · GHSA-89mh-mm8c-mv7f @apostrophecms/form (npm) Fixed in 1.5.5 Advisory →
Timeline
- 2026-10-20 Threatist record created from CVE-2026-113656
- 2026-10-21 Alias added: GHSA-89mh-mm8c-mv7f
- 2026-10-21 Fix available: npm/@apostrophecms/[email protected] · GHSA-89mh-mm8c-mv7f
- 2026-10-21 CVSS score added · GHSA-89mh-mm8c-mv7f
- 2026-10-21 Weakness changed · GHSA-89mh-mm8c-mv7f
- 2026-10-21 5 new references · GHSA-89mh-mm8c-mv7f
- 2026-10-21 CISA SSVC decision points changed
References
Other 5
- https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-89mh-mm8c-mv7f
- https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce
- https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350
- https://github.com/apostrophecms/apostrophe/releases/tag/@apostrophecms/[email protected]
- https://github.com/apostrophecms/apostrophe
More apostrophecms vulnerabilities
- TI-2026-25223 ApostropheCMS has Arbitrary File Write (Zip Slip / Path Traversal) in Import-Export Gzip Extraction CVSS 3.1CRITICAL 10.0
- TI-2026-32848 Apostrophe has default XSS via `xmp` raw-text passthrough in `sanitize-html` CVSS 3.1CRITICAL 9.3
- TI-2026-38664 @apostrophecms/seo Vulnerable to Stored XSS via Unsanitized Google Analytics / GTM ID Injected into Script Tag CVSS 3.1HIGH 8.7
- TI-2026-27673 ApostropheCMS: Stored XSS in SEO Fields Leads to Authenticated API Data Exposure in ApostropheCMS CVSS 3.1HIGH 8.7
- TI-2026-76992 Unauthenticated resource exhaustion via ApostropheCMS import routes CVSS 3.1HIGH 7.5
- TI-2026-76974 ApostropheCMS leaves rejected CSV uploads in temporary directory CVSS 3.1HIGH 7.5
Sources
- CVE-2026-113656 · CVE Program
- CVE-2026-113656 · NVD
- FIRST EPSS
- GHSA-89mh-mm8c-mv7f · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences