High severity · published Aug 17, 2026
CVE-2026-71553
ApostropheCMS: 2nd-order prototype pollution via PATCH leading to single-request persistent DoS
7.1
CVSS
0.4%
EPSS
No
On KEV
Description
ApostropheCMS is an open-source Node.js content management system. In 4.32.0 and earlier, PATCH /api/v1/article/:id accepts the inherited path toString.call and passes it through the utility module to apos.util.set() and apos.util.get(), allowing an authenticated editor to overwrite the shared Object.prototype.toString function's call property and cause a persistent process-wide denial of service until restart.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 37% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AP
apostrophe · apostrophecms
<= 4.32.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-71553
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-71553
github.com
https://github.com/apostrophecms/apostrophe/commit/5a3746aaed49761e171c2cbfe793267c959829fd
github.com
https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-vmg4-6gfg-83qx
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