CVE-2026-27760

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

Score 8.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-04-28. NVD baseline CVSS 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
8.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 22%CVSS: 8.1Exploit: NoneExposed: 0

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

OpenCATS prior to commit 3002a29 contains a PHP code injection vulnerability in the installer AJAX endpoint that allows unauthenticated attackers to execute arbitrary code by injecting PHP statements into the databaseConnectivity action parameter. Attackers can break out of the define() string context in config.php using a single quote and statement separator to inject malicious PHP code that persists and executes on every subsequent page load when the installation wizard remains incomplete.

CVSS v3
8.1
EG Score
8.1(medium)
EPSS
97.4%
KEV
Not listed

Published

April 28, 2026

Last Modified

July 14, 2026

Advisory Details (5)

Auto-updated May 4, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic

security: restrict AJAX during upgrade and escape installer config writes by anonymoususer72041 · Pull Request #706 · opencats/OpenCATS · GitHub

https://github.com/opencats/OpenCATS/pull/706
generic

security: restrict AJAX during upgrade and escape installer config wr… · opencats/OpenCATS@3002a29 · GitHub

https://github.com/opencats/OpenCATS/commit/3002a29f4c3cada1aa2c4f3d4ae4e189906606b6
generic

OpenCATS/modules/install/ajax/ui.php at 46e47273965130c042dd213ebfd0dde2bbe5046c · opencats/OpenCATS · GitHub

https://github.com/opencats/OpenCATS/blob/46e4727/modules/install/ajax/ui.php#L130
generic

OpenCATS/lib/CATSUtility.php at 46e47273965130c042dd213ebfd0dde2bbe5046c · opencats/OpenCATS · GitHub

https://github.com/opencats/OpenCATS/blob/46e4727/lib/CATSUtility.php#L142-L172
generic🔴 Active Exploitation

Unauthenticated RCE in OpenCATS via Installer Config Injection - Chocapikk's Cybersecurity Blog

https://chocapikk.com/posts/2026/opencats-installer-rce/

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 43× 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 151 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Nucleihttp/cves/2026/CVE-2026-27760.yaml
    First seen Jan 1, 2026

    OpenCATS - Command Injection

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-27760?
CVE-2026-27760 is a high vulnerability published on April 28, 2026. OpenCATS prior to commit 3002a29 contains a PHP code injection vulnerability in the installer AJAX endpoint that allows unauthenticated attackers to execute arbitrary code by injecting PHP statements into the databaseConnectivity action parameter. Attackers can break out of the define() string…
When was CVE-2026-27760 disclosed?
CVE-2026-27760 was first published in the National Vulnerability Database on April 28, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27760 actively exploited?
CVE-2026-27760 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 97.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-27760?
CVE-2026-27760 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-27760?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27760, 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.

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