CVE Intelligence
Medium Info disclosure exploit reference

CVE-2026-33888 — ApostropheCMS: publicApiProjection Bypass via `project` Query Builder in Piece-Type REST API

ApostropheCMS is an open-source Node.js content management system. Versions 4.28.0 and prior contain an authorization bypass vulnerability in the getRestQuery method of the @apostrophecms/piece-type module, where the method checks whether a MongoDB projection has already been set before applying the admin-configured publicApiProjection. An unauthenticated attacker can supply a project query parameter in the REST API request, which is processed by applyBuildersSafely before the permission check, pre-populating the projection state and causing the publicApiProjection to be skipped entirely. This allows disclosure of any field on publicly queryable documents that the administrator explicitly restricted from the public API, such as internal notes, draft content, or metadata. Exploitation is trivial, requiring only appending query parameters to a public URL with no authentication. This issue has been fixed in version 4.29.0.

Published Apr 15, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.5% (30-day exploitation probability)+6
  • Technical severity (medium)+3
  • CISA SSVC: exploitation "poc"+5
  • Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.52%
ahead of 43% of scored CVEs · Oct 14, 2026
Affects
Apostrophecms
Apostrophe and 1 more
CVSS base
5.3
Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Proof of concept
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — github.com (NIST National Vulnerability Database)
  • Documented patch — github.com (NIST National Vulnerability Database)
  • Documented mitigation — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Apostrophecms Apostrophe, Apostrophecms Apostrophecms).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. Search available logs for exploit probes matching the vulnerability class (info disclosure), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Apostrophecms Apostrophe version < 4.29.0 Vulnerable CVE Program (cve.org) e CISA ADP
Apostrophecms Apostrophecms < 4.29.0 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
5.3 CVSS 3.1 Medium 3.9 1.4 security-advisories@github.com via NIST National Vulnerability Database
5.3 CVSS 3.1 Medium — — GitHub_M via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-200 · Exposure of Sensitive Information

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.52%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Look for anomalous data read/export volumes and access to sensitive records.
web/proxy/WAF logsnetwork IDS/IPSapplication logsauthentication logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · apostrophecms/apostrophe
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 5.3
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    Apr 15, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

3 on the record

Elsewhere on this site

Apostrophecms
every CVE for this vendor
Info disclosure
same class
CWE-200
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-110904 Incorrect Authorization in Apostrophecms 20h
  • CVE-2026-53609 Apostrophe has Server-Side Prototype Pollution in apos.util.set via patch operators that leads to process-wide authorization bypass Jun 12, 2026
  • CVE-2026-53607 @apostrophecms/file pretty-URL Vulnerable to Unauthenticated SSRF via Host header Jun 12, 2026
  • CVE-2026-45011 Apostrophe has stored XSS via javascript: URL in Image Widget Link Jun 12, 2026
  • CVE-2026-45012 Apostrophe has authenticated SSRF in rich-text widget import via @apostrophecms/area/validate-widget Jun 12, 2026
  • CVE-2026-45013 Apostrophe has a Weak Password Recovery Mechanism for Forgotten Password and Improper Input Validation Jun 12, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-33888 is "ApostropheCMS: publicApiProjection Bypass via `project` Query Builder in Piece-Type REST API", rated Medium. It affects Apostrophe (Apostrophecms); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. EPSS 0.52% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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