CVE-2026-8406

HIGHPre-NVD 7.17.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 85% 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, secondary
7.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.1Exploit: None knownExposed: 0

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

openSIS Classic 9.3 contains an insecure direct object reference vulnerability in the messaging module. Any authenticated user with access to the messaging module can request sent-message details from modules/messaging/SentMail.php by supplying an arbitrary mail_id value.

CVSS v3
7.1
EG Score
7.1(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
Severity71% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
15%
KEV
Not listed

Published

June 11, 2026

Last Modified

June 11, 2026

Advisory Details (3)

Auto-updated Jun 11, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
generic

openSIS Classic 9.3 - Insecure Direct Object Reference in Sent Mail | Fluid Attacks

https://fluidattacks.com/es/advisories/melanie
github_commit

commit c45d43146167 (OS4ED/openSIS-Classic)

Fix landed in OS4ED/openSIS-Classic commit c45d43146167 — awaiting tagged release

https://github.com/OS4ED/openSIS-Classic/commit/c45d43146167324bae06bdf09de3e4bd2e5e478f
generic

GitHub - OS4ED/openSIS-Classic: openSIS is a commercial grade, secure, scalable & intuitive Student Information System, School Management Software from OS4ED. Has all functionalities to run single or multiple institutions in one installation. Web based, php code, MySQL database. · GitHub

https://github.com/OS4ED/openSIS-Classic

Vendor Advisories for CVE-2026-8406(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 6× in last 7d / 33× 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 242 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-8406?
CVE-2026-8406 is a high vulnerability published on June 11, 2026. openSIS Classic 9.3 contains an insecure direct object reference vulnerability in the messaging module. Any authenticated user with access to the messaging module can request sent-message details from modules/messaging/SentMail.php by supplying an arbitrary mail_id value.
When was CVE-2026-8406 disclosed?
CVE-2026-8406 was first published in the National Vulnerability Database on June 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-8406 actively exploited?
CVE-2026-8406 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 84.9% of all scored CVEs.
What is the CVSS score of CVE-2026-8406?
CVE-2026-8406 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2026-8406?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8406, 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

Explore the affected products and dependency analysis for CVE-2026-8406

Explore →

Is Your Infrastructure Affected by CVE-2026-8406?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs