CVE-2021-47964

HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-15. NVD baseline CVSS 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 8.8Exploit: NoneExposed: 0

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

Schlix CMS 2.2.6-6 contains a remote code execution vulnerability that allows authenticated attackers to execute arbitrary PHP code by uploading malicious extension packages through the block manager. Attackers can upload a crafted ZIP file containing PHP code in the packageinfo.inc file and trigger execution by accessing the About tab of the installed extension.

CVSS v3
8.8
EG Score
8.8(medium)
EPSS
49.2%
KEV
Not listed

Published

May 15, 2026

Last Modified

May 18, 2026

Advisory Details (3)

Auto-updated May 18, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

Schlix CMS 2.2.6-6 Remote Code Execution via core.blockmanager | Advisories | VulnCheck

https://www.vulncheck.com/advisories/schlix-cms-6-remote-code-execution-via-core-blockmanager
generic

SCHLIX - Free CMS, blog and website builder (open source) for PHP/MySQL

https://www.schlix.com/
generic🟡 PoC Available

Schlix CMS 2.2.6-6 - Remote Code Execution (Authenticated) - Multiple webapps Exploit

https://www.exploit-db.com/exploits/49838

Vendor Advisories for CVE-2021-47964(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 71× 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 200 total refreshes for this CVE.

  1. 2026-07-13 22:27 UTCEPSS rescore
  2. 2026-07-13 06:11 UTCEPSS rescore
  3. 2026-07-13 06:11 UTCEPSS rescore
  4. 2026-07-12 05:44 UTCEPSS rescore
  5. 2026-07-11 08:25 UTCEPSS rescore
  6. 2026-07-09 19:07 UTCEPSS rescore
  7. 2026-07-09 19:07 UTCEPSS rescore
  8. 2026-07-08 15:12 UTCEPSS rescore
  9. 2026-07-08 15:12 UTCEPSS rescore
  10. 2026-07-07 13:43 UTCEPSS rescore
  11. 2026-07-06 16:25 UTCEPSS rescore
  12. 2026-07-06 16:25 UTCEPSS rescore
  13. 2026-07-06 02:21 UTCEPSS rescore
  14. 2026-07-06 02:21 UTCEPSS rescore
  15. 2026-07-05 02:28 UTCEPSS rescore
  16. 2026-07-05 02:28 UTCEPSS rescore
  17. 2026-07-04 06:29 UTCEPSS rescore
  18. 2026-07-04 06:29 UTCEPSS rescore
  19. 2026-07-01 15:04 UTCEPSS rescore
  20. 2026-06-30 23:20 UTCEPSS rescore
  21. 2026-06-29 21:27 UTCEG score recompute
  22. 2026-06-29 21:27 UTCGHSA enrichment
  23. 2026-06-29 14:04 UTCEPSS rescore
  24. 2026-06-29 14:04 UTCEPSS rescore
  25. 2026-06-28 14:05 UTCEPSS rescore
Show 75 more
  1. 2026-06-28 09:28 UTCEG score recompute
  2. 2026-06-28 09:28 UTCGHSA enrichment
  3. 2026-06-28 04:54 UTCEPSS rescore
  4. 2026-06-28 04:54 UTCEPSS rescore
  5. 2026-06-27 21:51 UTCEG score recompute
  6. 2026-06-27 21:51 UTCGHSA enrichment
  7. 2026-06-27 07:46 UTCEG score recompute
  8. 2026-06-27 07:46 UTCGHSA enrichment
  9. 2026-06-27 03:07 UTCEPSS rescore
  10. 2026-06-27 03:06 UTCEPSS rescore
  11. 2026-06-26 20:10 UTCEG score recompute
  12. 2026-06-26 20:10 UTCGHSA enrichment
  13. 2026-06-25 18:44 UTCEG score recompute
  14. 2026-06-25 18:44 UTCGHSA enrichment
  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. 2026-06-22 14:24 UTCEPSS rescore
  22. 2026-06-21 14:55 UTCEPSS rescore
  23. 2026-06-21 01:58 UTCEPSS rescore
  24. 2026-06-21 01:58 UTCEPSS rescore
  25. 2026-06-19 19:24 UTCEPSS rescore
  26. 2026-06-19 19:24 UTCEPSS rescore
  27. 2026-06-18 17:51 UTCEPSS rescore
  28. 2026-06-18 17:51 UTCEPSS rescore
  29. 2026-06-18 03:53 UTCEG score recompute
  30. 2026-06-18 03:53 UTCGHSA enrichment
  31. 2026-06-17 17:51 UTCEPSS rescore
  32. 2026-06-17 17:51 UTCEPSS rescore
  33. 2026-06-17 13:22 UTCEG score recompute
  34. 2026-06-17 13:21 UTCGHSA enrichment
  35. 2026-06-16 22:43 UTCEG score recompute
  36. 2026-06-16 22:43 UTCGHSA enrichment
  37. 2026-06-16 17:51 UTCEPSS rescore
  38. 2026-06-16 11:06 UTCEG score recompute
  39. 2026-06-16 11:06 UTCGHSA enrichment
  40. 2026-06-15 23:32 UTCEG score recompute
  41. 2026-06-15 23:32 UTCGHSA enrichment
  42. 2026-06-15 17:46 UTCEPSS rescore
  43. 2026-06-14 23:15 UTCEPSS rescore
  44. 2026-06-14 23:15 UTCEPSS rescore
  45. 2026-06-14 22:21 UTCEG score recompute
  46. 2026-06-14 22:21 UTCGHSA enrichment
  47. 2026-06-14 10:48 UTCEG score recompute
  48. 2026-06-14 10:48 UTCGHSA enrichment
  49. 2026-06-13 23:14 UTCEG score recompute
  50. 2026-06-13 23:14 UTCGHSA enrichment
  51. 2026-06-13 22:58 UTCEPSS rescore
  52. 2026-06-13 22:58 UTCEPSS rescore
  53. 2026-06-13 06:43 UTCEG score recompute
  54. 2026-06-13 06:42 UTCGHSA enrichment
  55. 2026-06-12 23:10 UTCEPSS rescore
  56. 2026-06-12 19:08 UTCEG score recompute
  57. 2026-06-12 19:07 UTCGHSA enrichment
  58. 2026-06-12 07:32 UTCEG score recompute
  59. 2026-06-12 07:32 UTCGHSA enrichment
  60. 2026-06-11 19:59 UTCEG score recompute
  61. 2026-06-11 19:59 UTCGHSA enrichment
  62. 2026-06-11 13:58 UTCEPSS rescore
  63. 2026-06-11 08:25 UTCEG score recompute
  64. 2026-06-11 08:25 UTCGHSA enrichment
  65. 2026-06-10 22:16 UTCEPSS rescore
  66. 2026-06-10 20:52 UTCEG score recompute
  67. 2026-06-10 20:52 UTCGHSA enrichment
  68. 2026-06-10 13:20 UTCEPSS rescore
  69. 2026-06-10 09:12 UTCEG score recompute
  70. 2026-06-10 09:12 UTCGHSA enrichment
  71. 2026-06-09 21:39 UTCEG score recompute
  72. 2026-06-09 21:39 UTCGHSA enrichment
  73. 2026-06-09 09:58 UTCEG score recompute
  74. 2026-06-09 09:58 UTCGHSA enrichment
  75. 2026-06-08 22:26 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-47964?
CVE-2021-47964 is a high vulnerability published on May 15, 2026. Schlix CMS 2.2.6-6 contains a remote code execution vulnerability that allows authenticated attackers to execute arbitrary PHP code by uploading malicious extension packages through the block manager. Attackers can upload a crafted ZIP file containing PHP code in the packageinfo.inc file and…
When was CVE-2021-47964 disclosed?
CVE-2021-47964 was first published in the National Vulnerability Database on May 15, 2026, with the most recent update on May 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-47964 actively exploited?
CVE-2021-47964 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 49.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-47964?
CVE-2021-47964 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2021-47964?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-47964, 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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