CVE-2026-52889

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.7%, top 50% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Formie is a Craft CMS plugin for creating forms. Prior to 3.1.27, Formie can pass request-derived Hidden field defaults such as HTTP User Agent, Referer URL, Current URL, Current URL without Query String, Query Parameter, and Cookie Value to Craft's Twig rendering layer during front-end form rendering. An unauthenticated attacker can place Twig syntax in one of these request-controlled inputs when a public form contains an affected Hidden field. Hidden::getFrontEndInputOptions() then assigns the value to defaultValue and calls renderString, causing server-side template evaluation rather than treating the request data as a plain string. Depending on the Craft site configuration and available Twig capabilities, exploitation can disclose sensitive information, modify application state, or achieve remote code execution. This issue is fixed in version 3.1.27.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
59(Track)
EG Risk 59/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
50%
KEV
Not listed

Published

July 6, 2026

Last Modified

August 19, 2026

Advisory Details (3)

Auto-updated Aug 19, 2026
Patch available. Sources: github, github_commit, github_release.
github Patch Available

Server-Side Template Injection in Formie Hidden field defaults · Advisory · verbb/formie · GitHub

https://github.com/verbb/formie/security/advisories/GHSA-565m-g33j-jq96
github_release Patch Available

3.1.27

Patch available: verbb/formie 3.1.27

https://github.com/verbb/formie/releases/tag/3.1.27
github_commit Patch Available

commit d3b9d1529040 (verbb/formie)

Patch available: verbb/formie 3.1.27 (contains commit d3b9d1529040)

https://github.com/verbb/formie/commit/d3b9d15290405e484e3b5c91c5d8fab93047f9b2

Vendor Advisories for CVE-2026-52889(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
verbb/formie1.0.0 ... 3.1.9 (408 versions)3.1.27—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 13× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-25 16:00 UTCEG score recompute
  2. 2026-08-25 13:49 UTCEPSS rescore
  3. 2026-08-24 20:48 UTCEG score recompute
  4. 2026-08-24 10:02 UTCEG score recompute
  5. 2026-08-23 01:59 UTCEG score recompute
  6. 2026-08-23 00:19 UTCEPSS rescore
  7. 2026-08-22 04:48 UTCEG score recompute
  8. 2026-08-21 23:49 UTCEPSS rescore
  9. 2026-08-20 23:25 UTCEG score recompute
  10. 2026-08-20 22:55 UTCEPSS rescore
  11. 2026-08-19 18:20 UTCEG score recompute
  12. 2026-08-19 18:13 UTCEG score recompute
  13. 2026-07-30 12:45 UTCEG score recompute
  14. 2026-07-26 12:47 UTCEG score recompute
  15. 2026-07-23 03:19 UTCEG score recompute
  16. 2026-07-06 17:21 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-52889?
CVE-2026-52889 is a critical vulnerability published on July 6, 2026. Formie is a Craft CMS plugin for creating forms. Prior to 3.1.27, Formie can pass request-derived Hidden field defaults such as HTTP User Agent, Referer URL, Current URL, Current URL without Query String, Query Parameter, and Cookie Value to Craft's Twig rendering layer during front-end form…
When was CVE-2026-52889 disclosed?
CVE-2026-52889 was first published in the National Vulnerability Database on July 6, 2026, with the most recent update on August 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-52889 actively exploited?
CVE-2026-52889 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 50.3% of all scored CVEs.
What is the CVSS score of CVE-2026-52889?
CVE-2026-52889 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-52889?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-52889, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-52889

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