CVE Intelligence
Medium Input validation

CVE-2026-113667 — ApostropheCMS: CAPTCHA response token not URL-encoded

ApostropheCMS is an open-source Node.js content management system. Prior to 1.5.5 of the Form add-on, 1.2.1 of login-recaptcha, and 1.3.0 of login-hcaptcha, these three CAPTCHA integrations interpolate an unencoded user-supplied response token into the provider verification request. Crafted tokens can smuggle request parameters and disrupt CAPTCHA verification and CAPTCHA-gated form or login flows; automated bypass probing is possible, but a successful CAPTCHA bypass or secret disclosure is not established. This issue is fixed in Form 1.5.5, login-recaptcha 1.2.1, and login-hcaptcha 1.3.0.

Published Oct 20, 2026 · Updated Oct 20, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · 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
  • Technical severity (medium)+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
—
No EPSS score.
Affects
Apostrophecms
Apostrophe and 6 more
CVSS base
5.3
Medium · 2 source(s)

Remediation

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

  • Npm @apostrophecms/form: fixed in version 1.5.5 — github.com (GitHub Security Advisories)
  • Npm @apostrophecms/login-recaptcha: fixed in version 1.2.1 — github.com (GitHub Security Advisories)
  • Npm @apostrophecms/login-hcaptcha: fixed in version 1.3.0 — github.com (GitHub Security Advisories)

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 Form, Apostrophecms Login-hcaptcha…).
  2. Apply the fixed version or the patch documented under Remediation.
  3. Search available logs for exploit probes matching the vulnerability class (input validation), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Apostrophecms Apostrophe version < 4.33.0 Vulnerable CVE Program (cve.org) e CISA ADP
Apostrophecms Form version < 1.5.5 Vulnerable CVE Program (cve.org) e CISA ADP
Apostrophecms Login-hcaptcha version < 1.3.0 Vulnerable CVE Program (cve.org) e CISA ADP
Apostrophecms Login-recaptcha version < 1.2.1 Vulnerable CVE Program (cve.org) e CISA ADP
Npm @apostrophecms/form < 1.5.5 Vulnerable GitHub Security Advisories
Npm @apostrophecms/login-hcaptcha < 1.3.0 Vulnerable GitHub Security Advisories
Npm @apostrophecms/login-recaptcha < 1.2.1 Vulnerable GitHub Security Advisories

Attack characteristics

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

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
Low
User interaction
None
Scope
X
Confidentiality (vulnerable system)
Low
Integrity (vulnerable system)
Low
Availability (vulnerable system)
Low
Confidentiality (subsequent)
None
Integrity (subsequent)
None
Availability (subsequent)
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 4.0 Medium — — security-advisories@github.com via NIST National Vulnerability Database
5.3 CVSS 4.0 Medium — — GitHub_M via CVE Program (cve.org) e CISA ADP
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/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 (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-116 · Improper Encoding or Escaping of Output

Other CVEs with this weakness →

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).
web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

  • 2026
  • Source status changed · Received → Deferred
    Oct 20, 2026 · NIST National Vulnerability Database
  • Fix documented
    Oct 20, 2026 · GitHub Security Advisories
  • Affected products added · npm/@apostrophecms/form, npm/@apostrophecms/login-recaptcha, npm/@apostrophecms/login-hcaptcha
    Oct 20, 2026 · GitHub Security Advisories
  • Affected products added · apostrophecms/apostrophe, @apostrophecms/form, @apostrophecms/login-hcaptcha, @apostrophecms/login-recaptcha
    Oct 20, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 20, 2026
  • CVSS changed · 5.3
    Oct 20, 2026 · NIST National Vulnerability Database
  • Source status changed · → Received
    Oct 20, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 20, 2026 · Alertas do Telegram
  • CVE published
    Oct 20, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 20, 2026 – Oct 20, 2026
  • 1× Official description updated · Oct 20, 2026 – Oct 20, 2026

References

5 on the record

Elsewhere on this site

Apostrophecms
every CVE for this vendor
Input validation
same class
CWE-116
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-113711 ApostropheCMS: Unauthenticated resource exhaustion via pre-auth aposBigUpload processing in @apostrophecms/import-export 12h
  • CVE-2026-113710 ApostropheCMS: No Attempt Throttling on Authenticated Password-Change Endpoint Enables Unlimited Current-Password Guessing 12h
  • CVE-2026-113669 ApostropheCMS: Cross-domain session token in URL confers session takeover 12h
  • CVE-2026-113666 ApostropheCMS: Authenticated projection-exclusion prototype-member deletion in @apostrophecms/db-connect causes process-wide denial of service 12h
  • CVE-2026-113668 ApostropheCMS: :_id/locales REST route omits the public-API authorization gate its sibling read routes enforce (unauthenticated doc-existence + locale metadata disclosure) 12h
  • CVE-2026-113670 ApostropheCMS: Page REST API authorization bypass 12h

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 FIRST EPSS score.
  • No CISA SSVC assessment.
  • 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-2026-113667 is "ApostropheCMS: CAPTCHA response token not URL-encoded", 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. 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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