Medium severity · published Oct 20, 2026
CVE-2026-113656
ApostropheCMS: Unauthenticated unbounded multipart upload → disk-exhaustion DoS
5.3
CVSS
0.5%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AP
apostrophe · apostrophecms
< 4.33.0 · source: vendor
FO
form · @apostrophecms
< 1.5.5 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-113656
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-113656
github.com
https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce
github.com
https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350
github.com
https://github.com/apostrophecms/apostrophe/releases/tag/@apostrophecms/form@1.5.5
github.com
https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-89mh-mm8c-mv7f
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