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Response snapshot Oct 27, 2026, 10:42 UTC

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VulnerabilityCVE-2026-113667

ApostropheCMS: CAPTCHA response token not URL-encoded

**Summary** Form and login CAPTCHA verification interpolate the user-supplied widget token unencoded into the server-side verification URL/body, allowing a crafted token to inject query parameters into the reCAPTCHA/hCaptcha verify request. **Details** - `packages/form/lib/recaptcha.

At a glance

Exploited
Not known
Severity
5.3 Medium (CVSS 4.0)
Chance of exploitation
0.4% in the next 30 days
Sources
1 source

What to do

GitHub lists first patched versions: @apostrophecms/form: 1.5.5; @apostrophecms/login-recaptcha: 1.2.1; @apostrophecms/login-hcaptcha: 1.3.0. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-44qr-rrjg-2cqq (opens a new tab)

What happened

**Summary** Form and login CAPTCHA verification interpolate the user-supplied widget token unencoded into the server-side verification URL/body, allowing a crafted token to inject query parameters into the reCAPTCHA/hCaptcha verify request.

**Details** - `packages/form/lib/recaptcha.js:39` — `recaptchaUri = 'https://www.google.com/recaptcha/api/siteverify?secret=${recaptchaSecret}&response=${input.recaptcha}'` - `packages/login-recaptcha/index.js:44` — same pattern for login - `packages/login-hcaptcha/index.js:47` — `body: 'response=${token}&secret=${secret}'`

**PoC** ``` input.recaptcha = 'attacker_token&secret=INJECTED_SECRET&something=1' → resulting verify URL: https://www.google.com/recaptcha/api/siteverify?secret= &response=attacker_token&secret=INJECTED_SECRET&something=1 # (replicated exactly from recaptcha.js:39) ```

**Impact** Low: a crafted token smuggles extra `key=value` pairs (`secret`, extra `response`) into the outbound verify call, forcing verification failures (DoS of the captcha gate and of captcha-gated login/form flows) and enabling automated bypass probing; no secret exfiltration.

Continue reading

**Remediation** — Build the verify request with `URL` + `searchParams` (or `encodeURIComponent` on both `secret` and `response`), and validate the token against `^[A-Za-z0-9._-]{1,2048}$` before use.

Affected package ranges reported by GitHub: @apostrophecms/form: < 1.5.5 @apostrophecms/login-recaptcha: < 1.2.1 @apostrophecms/login-hcaptcha: < 1.3.0

Scores and how they were measured

CVSS base severity

5.3

Version 4.0As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.4%

Scored Percentile 30.2%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-44qr-rrjg-2cqq (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-44qr-rrjg-2cqq, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  3. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-44qr-rrjg-2cqq, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  4. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-44qr-rrjg-2cqq, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  5. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-113667, scored 2026-10-26. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 20). ApostropheCMS: CAPTCHA response token not URL-encoded (CVE-2026-113667). https://kevwire.com/record/CVE-2026-113667

MLA

"ApostropheCMS: CAPTCHA response token not URL-encoded (CVE-2026-113667)." KEVWire, 20 Oct. 2026, kevwire.com/record/CVE-2026-113667.

Chicago

KEVWire. "ApostropheCMS: CAPTCHA response token not URL-encoded (CVE-2026-113667)." Last modified October 20, 2026. https://kevwire.com/record/CVE-2026-113667.

Evidence summary (plain text)

ApostropheCMS: CAPTCHA response token not URL-encoded (Oct 20, 2026).
**Summary**
Form and login CAPTCHA verification interpolate the user-supplied widget token unencoded into the server-side verification URL/body, allowing a crafted token to inject query parameters into the reCAPTCHA/hCaptcha verify request.

**Details**
- `packages/form/lib/recaptcha.js:39` — `recaptchaUri = 'https://www.google.com/recaptcha/api/siteverify?secret=${recaptchaSecret}&response=${input.recaptcha}'`
- `packages/login-recaptcha/index.js:44` — same pattern for login
- `packages/login-hcaptcha/index.js:47` — `body: 'response=${token}&secret=${secret}'`
CVSS 5.3 (version 4.0; evidence as of Oct 20, 2026; https://github.com/advisories/GHSA-44qr-rrjg-2cqq).
EPSS 0.4% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-113667&date=2026-10-26).
Sources:
GitHub-reviewed advisory GHSA-44qr-rrjg-2cqq: https://github.com/advisories/GHSA-44qr-rrjg-2cqq
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yMVQyMDo0NTowN1rOAAfvzQ%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yMVQyMDozMDoyNlrOAAfvxw%3D%3D
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc&after=Y3Vyc29yOnYyOpK0MjAyNi0xMC0yMVQyMDowMzo1N1rOAAfvxQ%3D%3D
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-113667&date=2026-10-26
Record ID: CVE-2026-113667.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 07:41 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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