CVE-2021-29440

HIGHNVD 8.48.4
EchelonGraph scoreLOW confidence

This high-severity CVE scores 8.4 under NVD CVSS v3. EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). 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: nvd
Elevated
8.4
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 31%CVSS: 8.4Exploit: NoneExposed: 0

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

Grav is a file based Web-platform. Twig processing of static pages can be enabled in the front matter by any administrative user allowed to create or edit pages. As the Twig processor runs unsandboxed, this behavior can be used to gain arbitrary code execution and elevate privileges on the instance. The issue was addressed in version 1.7.11.

CVSS v3
8.4
EG Score
8.4(low)
EPSS
98.0%
KEV
Not listed

Published

April 13, 2021

Last Modified

November 21, 2024

References (8)

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
getgrav/grav0.8.0 ... 1.7.9 (229 versions)1.7.11—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 31× 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. 2026-07-11 08:25 UTCEPSS rescore
  2. 2026-07-11 08:25 UTCEPSS rescore
  3. 2026-07-09 19:07 UTCEPSS rescore
  4. 2026-07-08 15:12 UTCEPSS rescore
  5. 2026-07-06 16:25 UTCEPSS rescore
  6. 2026-07-06 16:25 UTCEPSS rescore
  7. 2026-07-05 02:28 UTCEPSS rescore
  8. 2026-07-02 16:57 UTCEPSS rescore
  9. 2026-07-01 15:03 UTCEPSS rescore
  10. 2026-06-28 14:05 UTCEPSS rescore
  11. 2026-06-28 04:54 UTCEPSS rescore
  12. 2026-06-28 04:54 UTCEPSS rescore
  13. 2026-06-27 03:06 UTCEPSS rescore
  14. 2026-06-27 03:06 UTCEPSS rescore
  15. 2026-06-25 13:48 UTCEPSS rescore
  16. 2026-06-25 13:48 UTCEPSS rescore
  17. 2026-06-24 14:03 UTCEPSS rescore
  18. 2026-06-24 14:03 UTCEPSS rescore
  19. 2026-06-23 21:31 UTCEPSS rescore
  20. 2026-06-23 21:31 UTCEPSS rescore
  21. 2026-06-21 01:58 UTCEPSS rescore
  22. 2026-06-21 01:58 UTCEPSS rescore
  23. 2026-06-18 17:51 UTCEPSS rescore
  24. 2026-06-18 17:51 UTCEPSS rescore
  25. 2026-06-17 17:51 UTCEPSS rescore
Show 34 more
  1. 2026-06-16 17:51 UTCEPSS rescore
  2. 2026-06-15 17:46 UTCEPSS rescore
  3. 2026-06-14 23:15 UTCEPSS rescore
  4. 2026-06-13 22:58 UTCEPSS rescore
  5. 2026-06-13 22:58 UTCEPSS rescore
  6. 2026-06-12 23:10 UTCEPSS rescore
  7. 2026-06-11 13:58 UTCEPSS rescore
  8. 2026-06-10 22:16 UTCEPSS rescore
  9. 2026-06-10 13:20 UTCEPSS rescore
  10. 2026-06-07 15:23 UTCEPSS rescore
  11. 2026-06-07 15:23 UTCEPSS rescore
  12. 2026-06-05 22:45 UTCEPSS rescore
  13. 2026-06-05 22:45 UTCEPSS rescore
  14. 2026-06-05 06:09 UTCEPSS rescore
  15. 2026-06-05 06:09 UTCEPSS rescore
  16. 2026-06-04 13:10 UTCEPSS rescore
  17. 2026-06-04 13:10 UTCEPSS rescore
  18. 2026-06-02 20:11 UTCEPSS rescore
  19. 2026-06-02 20:11 UTCEPSS rescore
  20. 2026-06-02 20:11 UTCEPSS rescore
  21. 2026-06-01 13:50 UTCEPSS rescore
  22. 2026-06-01 13:50 UTCEPSS rescore
  23. 2026-05-31 22:29 UTCEPSS rescore
  24. 2026-05-31 22:29 UTCEPSS rescore
  25. 2026-05-31 00:15 UTCEPSS rescore
  26. 2026-05-29 13:42 UTCEPSS rescore
  27. 2026-05-28 13:43 UTCEPSS rescore
  28. 2026-05-28 13:43 UTCEPSS rescore
  29. 2026-05-27 13:39 UTCEPSS rescore
  30. 2026-05-27 13:39 UTCEPSS rescore
  31. 2026-05-26 13:42 UTCEPSS rescore
  32. 2026-05-26 07:17 UTCEPSS rescore
  33. 2026-05-26 07:17 UTCEPSS rescore
  34. 2026-05-23 08:06 UTCEG score recompute

Publicly available exploits

(2 references)

Working exploit code is in the public domain (1 GitHub PoC) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-49961
    First seen Jun 7, 2021

    Grav CMS 1.7.10 - Server-Side Template Injection (SSTI) (Authenticated)

    Open source ↗
  • GitHub PoCCsEnox/CVE-2021-29440
    First seen Jun 6, 2021

    Unsafe Twig processing of static pages leading to RCE in Grav CMS 1.7.10

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-29440?
CVE-2021-29440 is a high vulnerability published on April 13, 2021. Grav is a file based Web-platform. Twig processing of static pages can be enabled in the front matter by any administrative user allowed to create or edit pages. As the Twig processor runs unsandboxed, this behavior can be used to gain arbitrary code execution and elevate privileges on the…
When was CVE-2021-29440 disclosed?
CVE-2021-29440 was first published in the National Vulnerability Database on April 13, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-29440 actively exploited?
CVE-2021-29440 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 98.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-29440?
CVE-2021-29440 has a CVSS v3 base score of 8.4 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2021-29440?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-29440, 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

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