CVE-2026-71553: ApostropheCMS: 2nd-order prototype pollution via PATCH leading to single-request persistent DoS
Vulnerability summary
CVE-2026-71553 is a high (CVSS 7.1) Prototype Pollution vulnerability in apostrophecms apostrophe. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36% of scored vulnerabilities.
Timeline
- 17-08-2026PublishedVulnerability first disclosed.
- 17-08-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · NpmEcosystem advisory · calculated7.1HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
- NVDNIST7.1HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS trend
Probability
0.43%
Chance of exploitation in the next 30 days
Percentile
36%
Versus all other CVEs
30-day change
Increase +0.12 pp
From 0.31% on 22-09-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Apostrophecms1 product
- apostrophe≤ 4.32.0
Npm1 product
- apostrophe≤ 4.32.0
2 vendors · 2 products