CVE-2021-47955

MEDIUMNVD 5.45.4—
EchelonGraph scoreMEDIUM confidence

Score 5.4 from GitHub Security Advisory published 2026-05-16. NVD baseline CVSS 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
5.4
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.4Exploit: NoneExposed: 0

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

CouchCMS 2.2.1 contains a cross-site scripting vulnerability that allows authenticated attackers to execute arbitrary JavaScript by uploading malicious SVG files through the file upload functionality. Attackers can upload SVG files containing embedded script tags to the browse.php endpoint, which are then executed in users' browsers when the files are accessed or previewed.

CVSS v3
5.4
EG Score
5.4(medium)
EPSS
6.9%
KEV
Not listed

Published

May 16, 2026

Last Modified

May 24, 2026

Advisory Details (3)

Auto-updated May 16, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

CouchCMS 2.2.1 Cross-Site Scripting via SVG File Upload | Advisories | VulnCheck

https://www.vulncheck.com/advisories/couchcms-cross-site-scripting-via-svg-file-upload
generic🟡 PoC Available

CouchCMS 2.2.1 - Persistent Cross-Site Scripting - PHP webapps Exploit

https://www.exploit-db.com/exploits/49636
generic

GitHub - CouchCMS/CouchCMS: Simple Open-Source CMS for designers · GitHub

https://github.com/CouchCMS/CouchCMS

Vendor Advisories for CVE-2021-47955(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 / 58× 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 164 total refreshes for this CVE.

  1. 2026-07-15 16:55 UTCEPSS rescore
  2. 2026-07-15 01:58 UTCEPSS rescore
  3. 2026-07-15 01:58 UTCEPSS rescore
  4. 2026-07-13 22:27 UTCEPSS rescore
  5. 2026-07-13 06:11 UTCEPSS rescore
  6. 2026-07-13 06:11 UTCEPSS rescore
  7. 2026-07-11 08:25 UTCEPSS rescore
  8. 2026-07-09 19:07 UTCEPSS rescore
  9. 2026-07-09 19:07 UTCEPSS rescore
  10. 2026-07-08 15:12 UTCEPSS rescore
  11. 2026-07-08 15:12 UTCEPSS rescore
  12. 2026-07-07 13:43 UTCEPSS rescore
  13. 2026-07-06 16:25 UTCEPSS rescore
  14. 2026-07-06 16:25 UTCEPSS rescore
  15. 2026-07-06 02:21 UTCEPSS rescore
  16. 2026-07-06 02:21 UTCEPSS rescore
  17. 2026-07-05 02:28 UTCEPSS rescore
  18. 2026-07-05 02:28 UTCEPSS rescore
  19. 2026-07-04 06:29 UTCEPSS rescore
  20. 2026-07-04 06:29 UTCEPSS rescore
  21. 2026-07-01 15:04 UTCEPSS rescore
  22. 2026-06-30 23:20 UTCEPSS rescore
  23. 2026-06-29 21:18 UTCEG score recompute
  24. 2026-06-29 21:18 UTCGHSA enrichment
  25. 2026-06-29 14:04 UTCEPSS rescore
Show 75 more
  1. 2026-06-29 14:04 UTCEPSS rescore
  2. 2026-06-28 14:05 UTCEPSS rescore
  3. 2026-06-28 04:54 UTCEPSS rescore
  4. 2026-06-28 04:54 UTCEPSS rescore
  5. 2026-06-27 21:43 UTCEG score recompute
  6. 2026-06-27 21:43 UTCGHSA enrichment
  7. 2026-06-27 03:07 UTCEPSS rescore
  8. 2026-06-27 03:06 UTCEPSS rescore
  9. 2026-06-26 20:03 UTCEG score recompute
  10. 2026-06-26 20:03 UTCGHSA enrichment
  11. 2026-06-25 18:37 UTCEG score recompute
  12. 2026-06-25 18:37 UTCGHSA enrichment
  13. 2026-06-25 13:48 UTCEPSS rescore
  14. 2026-06-25 13:48 UTCEPSS rescore
  15. 2026-06-24 14:03 UTCEPSS rescore
  16. 2026-06-24 14:03 UTCEPSS rescore
  17. 2026-06-23 21:31 UTCEPSS rescore
  18. 2026-06-23 21:31 UTCEPSS rescore
  19. 2026-06-22 14:24 UTCEPSS rescore
  20. 2026-06-21 14:55 UTCEPSS rescore
  21. 2026-06-21 01:58 UTCEPSS rescore
  22. 2026-06-21 01:58 UTCEPSS rescore
  23. 2026-06-19 19:24 UTCEPSS rescore
  24. 2026-06-19 19:24 UTCEPSS rescore
  25. 2026-06-18 17:51 UTCEPSS rescore
  26. 2026-06-18 17:51 UTCEPSS rescore
  27. 2026-06-18 02:48 UTCEG score recompute
  28. 2026-06-18 02:48 UTCGHSA enrichment
  29. 2026-06-17 17:51 UTCEPSS rescore
  30. 2026-06-17 17:51 UTCEPSS rescore
  31. 2026-06-17 00:19 UTCEG score recompute
  32. 2026-06-17 00:19 UTCGHSA enrichment
  33. 2026-06-16 17:51 UTCEPSS rescore
  34. 2026-06-15 23:23 UTCEG score recompute
  35. 2026-06-15 23:23 UTCGHSA enrichment
  36. 2026-06-15 17:46 UTCEPSS rescore
  37. 2026-06-14 23:15 UTCEPSS rescore
  38. 2026-06-14 23:15 UTCEPSS rescore
  39. 2026-06-14 16:19 UTCEG score recompute
  40. 2026-06-14 16:19 UTCGHSA enrichment
  41. 2026-06-13 22:58 UTCEPSS rescore
  42. 2026-06-13 22:58 UTCEPSS rescore
  43. 2026-06-13 15:16 UTCEG score recompute
  44. 2026-06-13 15:16 UTCGHSA enrichment
  45. 2026-06-12 23:10 UTCEPSS rescore
  46. 2026-06-12 14:24 UTCEG score recompute
  47. 2026-06-12 14:24 UTCGHSA enrichment
  48. 2026-06-11 13:58 UTCEPSS rescore
  49. 2026-06-11 13:34 UTCEG score recompute
  50. 2026-06-11 13:34 UTCGHSA enrichment
  51. 2026-06-10 22:16 UTCEPSS rescore
  52. 2026-06-10 13:20 UTCEPSS rescore
  53. 2026-06-10 12:45 UTCEG score recompute
  54. 2026-06-10 12:45 UTCGHSA enrichment
  55. 2026-06-09 11:56 UTCEG score recompute
  56. 2026-06-09 11:56 UTCGHSA enrichment
  57. 2026-06-08 14:15 UTCEPSS rescore
  58. 2026-06-08 14:15 UTCEPSS rescore
  59. 2026-06-08 14:15 UTCEPSS rescore
  60. 2026-06-08 11:07 UTCEG score recompute
  61. 2026-06-08 11:07 UTCGHSA enrichment
  62. 2026-06-07 15:23 UTCEPSS rescore
  63. 2026-06-07 15:23 UTCEPSS rescore
  64. 2026-06-07 10:18 UTCEG score recompute
  65. 2026-06-07 10:18 UTCGHSA enrichment
  66. 2026-06-06 13:46 UTCEPSS rescore
  67. 2026-06-06 13:46 UTCEPSS rescore
  68. 2026-06-06 09:29 UTCEG score recompute
  69. 2026-06-06 09:29 UTCGHSA enrichment
  70. 2026-06-05 22:45 UTCEPSS rescore
  71. 2026-06-05 22:45 UTCEPSS rescore
  72. 2026-06-05 08:41 UTCEG score recompute
  73. 2026-06-05 08:41 UTCGHSA enrichment
  74. 2026-06-05 06:09 UTCEPSS rescore
  75. 2026-06-05 06:09 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2021-47955?
CVE-2021-47955 is a medium vulnerability published on May 16, 2026. CouchCMS 2.2.1 contains a cross-site scripting vulnerability that allows authenticated attackers to execute arbitrary JavaScript by uploading malicious SVG files through the file upload functionality. Attackers can upload SVG files containing embedded script tags to the browse.php endpoint, which…
When was CVE-2021-47955 disclosed?
CVE-2021-47955 was first published in the National Vulnerability Database on May 16, 2026, with the most recent update on May 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-47955 actively exploited?
CVE-2021-47955 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 6.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-47955?
CVE-2021-47955 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2021-47955?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-47955, 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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