CVE-2021-29454

HIGHNVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under NVD CVSS v3. EPSS exploit probability: 1.9%, top 22% 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, nvd
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 2%CVSS: 8.1Exploit: None knownExposed: 0

A fix is available — apply it.

Smarty is a template engine for PHP, facilitating the separation of presentation (HTML/CSS) from application logic. Prior to versions 3.1.42 and 4.0.2, template authors could run arbitrary PHP code by crafting a malicious math string. If a math string was passed through as user provided data to the math function, external users could run arbitrary PHP code by crafting a malicious math string. Users should upgrade to version 3.1.42 or 4.0.2 to receive a patch.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: 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
Severity81% × 45%
Exploitation2% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
2%
EPSS %ILE
79%
KEV
Not listed

Published

January 10, 2022

Last Modified

November 21, 2024

Advisory Details (10)

Auto-updated Sep 16, 2026
Patch available. Sources: github_release, github, github_commit.
generic

[SECURITY] [DSA 5151-1] smarty3 security update

https://www.debian.org/security/2022/dsa-5151
generic

Smarty: Multiple vulnerabilities (GLSA 202209-09) — Gentoo security

https://security.gentoo.org/glsa/202209-09
generic

smarty/smarty - Packagist.org

https://packagist.org/packages/smarty/smarty
generic

[SECURITY] Fedora 36 Update: php-Smarty-3.1.47-1.fc36 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L777JIBIWJV34HS7LXPIDWASG7TT4LNI/
generic

[SECURITY] Fedora 37 Update: php-Smarty-3.1.47-1.fc37 - package-announce - Fedora mailing-lists

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BRAJVDRGCIY5UZ2PQHKDTT7RMKG6WJQQ/
generic Patch Available

[SECURITY] [DLA 2995-1] smarty3 security update

https://lists.debian.org/debian-lts-announce/2022/05/msg00005.html
github Patch Available

Sandbox Escape by math function · Advisory · smarty-php/smarty · GitHub

https://github.com/smarty-php/smarty/security/advisories/GHSA-29gp-2c3m-3j6m
github_release Patch Available

v4.0.2

Patch available: smarty-php/smarty v4.0.2

https://github.com/smarty-php/smarty/releases/tag/v4.0.2
github_release Patch Available

v3.1.42

Patch available: smarty-php/smarty v3.1.42

https://github.com/smarty-php/smarty/releases/tag/v3.1.42
github_commit Patch Available

commit 215d81a9fa3c (smarty-php/smarty)

Patch available: smarty-php/smarty v4.5.1 (contains commit 215d81a9fa3c)

https://github.com/smarty-php/smarty/commit/215d81a9fa3cd63d82fb3ab56ecaf97cf1e7db71

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntusmarty3 (3.1.21-1ubuntu1+esm1) @ xenial2026-05-26ubuntu
ubuntusmarty3 (3.1.34+20190228.1.c9f0de05+selfpack1-1ubuntu0.1~esm1) @ focal2026-05-26ubuntu
ubuntusmarty3 (3.1.39-2ubuntu0.21.10.1) @ impish2026-05-26ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(10 across 7 ecosystems)
Debian:12(2)
PackageVulnerable rangeFixed inDependents
smarty3—3.1.45-1—
smarty4—4.1.1-1—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
smarty3—3.1.45-1—
smarty4—4.1.1-1—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
smarty3—3.1.45-1—
smarty4—4.1.1-1—
Debian:10(1)
PackageVulnerable rangeFixed inDependents
smarty33.1.33+20180830.1.3a78a21f+selfpack1-13.1.33+20180830.1.3a78a21f+selfpack1-1+deb10u1—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
smarty33.1.39-1, 3.1.39-23.1.39-2+deb11u1—
Debian:9(1)
PackageVulnerable rangeFixed inDependents
smarty33.1.31+20161214.1.c7d42e4+selfpack1-2, 3.1.31+20161214.1.c7d42e4+selfpack1-2+deb9u1, 3.1.31+20161214.1.c7d42e4+selfpack1-2+deb9u2, 3.1.31+20161214.1.c7d42e4+selfpack1-2+deb9u3, 3.1.31+20161214.1.c7d42e4+selfpack1-2+deb9u43.1.31+20161214.1.c7d42e4+selfpack1-2+deb9u5—
Packagist(1)
PackageVulnerable rangeFixed inDependents
smarty/smartyv4.0.0, v4.0.14.0.2—

Weakness Classification(1)

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

All Vendor Advisories

(3)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 8× 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.

Showing the most recent 100 of 166 total refreshes for this CVE.

  1. 2026-09-19 15:37 UTCEPSS rescore
  2. 2026-09-18 19:23 UTCEPSS rescore
  3. 2026-09-17 19:23 UTCEPSS rescore
  4. 2026-09-17 19:23 UTCEPSS rescore
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  6. 2026-09-15 03:06 UTCEPSS rescore
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  10. 2026-09-11 14:49 UTCEPSS rescore
  11. 2026-09-11 09:33 UTCEPSS rescore
  12. 2026-09-08 21:56 UTCEPSS rescore
  13. 2026-09-07 15:58 UTCEPSS rescore
  14. 2026-09-06 13:44 UTCEPSS rescore
  15. 2026-09-06 00:25 UTCOSV refresh
  16. 2026-09-05 15:25 UTCEPSS rescore
  17. 2026-09-04 13:57 UTCEPSS rescore
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  20. 2026-09-02 14:08 UTCEPSS rescore
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  22. 2026-09-01 03:32 UTCEPSS rescore
  23. 2026-08-30 19:14 UTCEPSS rescore
  24. 2026-08-30 01:19 UTCEPSS rescore
  25. 2026-08-28 21:37 UTCEPSS rescore
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  1. 2026-08-27 14:22 UTCEPSS rescore
  2. 2026-08-26 14:42 UTCEPSS rescore
  3. 2026-08-25 13:45 UTCEPSS rescore
  4. 2026-08-24 14:12 UTCEPSS rescore
  5. 2026-08-23 00:16 UTCEPSS rescore
  6. 2026-08-21 23:46 UTCEPSS rescore
  7. 2026-08-20 22:52 UTCEPSS rescore
  8. 2026-08-19 17:01 UTCEPSS rescore
  9. 2026-08-19 11:29 UTCOSV refresh
  10. 2026-08-18 13:45 UTCEPSS rescore
  11. 2026-08-17 13:44 UTCEPSS rescore
  12. 2026-08-16 14:53 UTCEPSS rescore
  13. 2026-08-16 02:11 UTCEPSS rescore
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  15. 2026-08-15 01:27 UTCEPSS rescore
  16. 2026-08-13 21:57 UTCEPSS rescore
  17. 2026-08-12 13:47 UTCEPSS rescore
  18. 2026-08-11 13:38 UTCEPSS rescore
  19. 2026-08-09 13:43 UTCEPSS rescore
  20. 2026-08-08 16:33 UTCEPSS rescore
  21. 2026-08-07 16:23 UTCEPSS rescore
  22. 2026-08-06 13:43 UTCEPSS rescore
  23. 2026-08-05 19:14 UTCEPSS rescore
  24. 2026-08-04 15:06 UTCEPSS rescore
  25. 2026-08-04 10:34 UTCEPSS rescore
  26. 2026-08-04 07:27 UTCOSV refresh
  27. 2026-08-03 10:33 UTCEPSS rescore
  28. 2026-08-02 02:24 UTCEPSS rescore
  29. 2026-08-01 04:13 UTCEPSS rescore
  30. 2026-07-30 16:25 UTCEPSS rescore
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  32. 2026-07-30 01:28 UTCEPSS rescore
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  35. 2026-07-26 14:52 UTCEPSS rescore
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  37. 2026-07-25 14:15 UTCEPSS rescore
  38. 2026-07-24 14:15 UTCEPSS rescore
  39. 2026-07-23 14:16 UTCEPSS rescore
  40. 2026-07-23 01:59 UTCEG score recompute
  41. 2026-07-22 22:46 UTCEG score recompute
  42. 2026-07-22 14:06 UTCEPSS rescore
  43. 2026-07-22 14:06 UTCEPSS rescore
  44. 2026-07-21 15:22 UTCEPSS rescore
  45. 2026-07-21 15:22 UTCEPSS rescore
  46. 2026-07-20 17:05 UTCEPSS rescore
  47. 2026-07-19 14:28 UTCEPSS rescore
  48. 2026-07-19 02:27 UTCEPSS rescore
  49. 2026-07-19 02:27 UTCEPSS rescore
  50. 2026-07-18 10:02 UTCEPSS rescore
  51. 2026-07-18 10:02 UTCEPSS rescore
  52. 2026-07-18 04:29 UTCOSV refresh
  53. 2026-07-16 17:00 UTCEPSS rescore
  54. 2026-07-15 16:55 UTCEPSS rescore
  55. 2026-07-15 16:55 UTCEPSS rescore
  56. 2026-07-15 01:58 UTCEPSS rescore
  57. 2026-07-13 22:27 UTCEPSS rescore
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  59. 2026-07-13 06:10 UTCEPSS rescore
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  62. 2026-07-11 08:25 UTCEPSS rescore
  63. 2026-07-11 08:25 UTCEPSS rescore
  64. 2026-07-09 19:07 UTCEPSS rescore
  65. 2026-07-08 15:12 UTCEPSS rescore
  66. 2026-07-07 13:43 UTCEPSS rescore
  67. 2026-07-06 16:25 UTCEPSS rescore
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  69. 2026-07-06 02:21 UTCEPSS rescore
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  71. 2026-07-05 02:28 UTCEPSS rescore
  72. 2026-07-04 06:29 UTCEPSS rescore
  73. 2026-07-04 06:29 UTCEPSS rescore
  74. 2026-07-02 16:57 UTCEPSS rescore
  75. 2026-07-01 15:03 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-29454?
CVE-2021-29454 is a high vulnerability published on January 10, 2022. Smarty is a template engine for PHP, facilitating the separation of presentation (HTML/CSS) from application logic. Prior to versions 3.1.42 and 4.0.2, template authors could run arbitrary PHP code by crafting a malicious math string. If a math string was passed through as user provided data to the…
When was CVE-2021-29454 disclosed?
CVE-2021-29454 was first published in the National Vulnerability Database on January 10, 2022, 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-2021-29454 actively exploited?
CVE-2021-29454 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2% probability of exploitation in the next 30 days, which ranks it in the top 20.9% of all scored CVEs.
What is the CVSS score of CVE-2021-29454?
CVE-2021-29454 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2021-29454?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-29454, 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-2021-29454

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