GHSA-vmg4-6gfg-83qx CVE-2026-71553
ApostropheCMS: 2nd-order prototype pollution via PATCH leading to single-request persistent DoS
- Severity
- 7.1 / 10
- High · CVSS 4.0
- Exploit chance (EPSS)
- 0.43%
- Chance of exploitation in the next 30 days. Higher than 37.17% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-1321 Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
- Fix
4.32.1- Upgrade apostrophe to this version or later
Description
The vulnerability is a single-request persistent DoS by submitting e.g. "PATCH /api/v1/article/<id>" with a valid editor session and body of {"toString.call":"x"}, overwriting the global toString function with value x.
Fabian
Affected versions
npm
| Package | Vulnerable | Fixed in |
|---|---|---|
| apostrophe | <= 4.32.0 |
No fix yet |
| apostrophe | < 4.32.1 |
4.32.1 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
apostrophe npm → 4.32.1
- npm
npm install apostrophe@4.32.1- yarn
yarn add apostrophe@4.32.1- pnpm
pnpm add apostrophe@4.32.1
Severity breakdown
CVSS 4.0 7.1
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- Low
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- Low
- Availability (vulnerable system)
- High
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
Weakness
CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
How to prevent it
- Implementation: By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.
- Architecture and Design: By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.
- Implementation: When handling untrusted objects, validating using a schema can be used.
- Implementation: By using an object without prototypes (via Object.create(null) ), adding object prototype attributes by accessing the prototype via the special attributes becomes impossible, mitigating this weakness.
- Implementation: Map can be used instead of objects in most cases. If Map methods are used instead of object attributes, it is not possible to access the object prototype or modify it.
References
Advisories
Fixes and patches
Packages
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-86wm-68pq-5jwq ApostropheCMS: Unauthenticated resource exhaustion via pre-auth aposBigUpload processing in @apostrophecms/import-export | High | Also affects apostrophe |
| GHSA-653j-g8j7-gh54 ApostropheCMS: No Attempt Throttling on Authenticated Password-Change Endpoint Enables Unlimited Current-Password Guessing | Medium | Also affects apostrophe |
| GHSA-vwwx-px9w-crrc ApostropheCMS: Missing Authorization on Notification PATCH/DELETE Endpoints | Low | Also affects apostrophe |
| GHSA-vmxh-77cw-65j7 ApostropheCMS: Authenticated Object-Level Authorization Bypass in exist-in-locale Reveals Restricted Localized Draft Identifiers | Medium | Also affects apostrophe |
| GHSA-m2m5-rw3w-cwmj ApostropheCMS: Client-side Prototype Pollution in apos.http.parseQuery leading to DOM-based XSS against authenticated users | Medium | Also affects apostrophe |
| GHSA-gqh3-7856-rjjg ApostropheCMS: :_id/locales REST route omits the public-API authorization gate its sibling read routes enforce (unauthenticated doc-existence + locale metadata disclosure) | Medium | Also affects apostrophe |
| GHSA-hhvr-8m24-qqr3 ApostropheCMS: Cross-domain session token in URL confers session takeover | Medium | Also affects apostrophe |
| GHSA-j5rq-xfvr-p969 ApostropheCMS: Authenticated projection-exclusion prototype-member deletion in @apostrophecms/db-connect causes process-wide denial of service | High | Also affects apostrophe |
Credits: breakingsystems, zuhairhalawa
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