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.
CVE-2026-8406
“—” beside the score: it is equal to the CVSS score beside it.
This high-severity CVE scores 7.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (33rd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
- High severity, but no confirmed exploitation yet
An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.
- CVSS v3
- 7.1
- EG Score
- 7.1HIGHmedium confidence
- EG Risk
- 32EG Risk 32/100
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 (value × EchelonGraph’s weight)Severity71% × 45%The EG Score, 7.1 of 10.Exploitation0.4% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release. - EPSS PROB
- 0.4%
- EPSS %ILE
- 33rd
- KEV
- Not listed
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
June 11, 2026
Last Modified
June 11, 2026
Advisory Details (3)
Auto-updated Jun 11, 2026openSIS Classic 9.3 - Insecure Direct Object Reference in Sent Mail | Fluid Attacks
https://fluidattacks.com/es/advisories/melaniecommit c45d43146167 (OS4ED/openSIS-Classic)
Fix landed in OS4ED/openSIS-Classic commit c45d43146167 — awaiting tagged release
https://github.com/OS4ED/openSIS-Classic/commit/c45d43146167324bae06bdf09de3e4bd2e5e478fGitHub - 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-ClassicVendor 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 10× in last 7d / 31× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 97 of 261 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 3 repeat rows among the latest 100 are merged into the row they repeat. The 164 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-11 19:18 UTCEG score recompute
- 2026-10-11 16:35 UTCEG score recompute
- 2026-10-11 13:52 UTCEG score recompute
- 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-10-03 08:39 UTCOSV refresh
- 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-27 13:49 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
- 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-17 19:32 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-16 14:09 UTCEPSS rescoreEPSS 0.2% · 14th percentile
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- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-14 04:10 UTCEG score recompute
- 2026-09-14 04:10 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-09-13 16:48 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-12 15:02 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-06 13:48 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-31 00:04 UTCEG score recompute
- 2026-08-31 00:04 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-30 19:18 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-26 14:47 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-25 00:03 UTCEG score recompute
- 2026-08-25 00:03 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-24 14:18 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-23 23:49 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-23 10:43 UTCEG score recompute
- 2026-08-23 10:43 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-22 01:20 UTCEG score recompute
- 2026-08-22 01:20 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-21 12:13 UTCEG score recompute
- 2026-08-21 12:13 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-20 22:56 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-20 22:16 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-20 08:51 UTCEG score recompute
- 2026-08-20 08:51 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-19 14:53 UTCEG score recompute
- 2026-08-19 14:53 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-18 13:49 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-17 15:16 UTCEG score recompute
- 2026-08-17 15:16 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-17 02:06 UTCEG score recompute
- 2026-08-17 02:06 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-16 12:59 UTCEG score recompute
- 2026-08-16 12:59 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-16 02:15 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-15 23:53 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-15 10:46 UTCEG score recompute
- 2026-08-15 10:46 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-15 01:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-14 16:57 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-14 03:50 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-13 14:44 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-13 00:26 UTCEG score recompute
- 2026-08-13 00:26 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-12 11:20 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-11 22:13 UTCEG score recompute
- 2026-08-11 22:13 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-11 13:43 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-11 09:03 UTCEG score recompute
- 2026-08-11 09:03 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-10 19:56 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-10 04:50 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
- 2026-08-09 15:43 UTCEG score recompute
- 2026-08-09 15:43 UTCGHSA enrichmentGHSA-vgf3-fpxc-h968 · GitHub severity HIGH
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Frequently asked(5)
What is CVE-2026-8406?
When was the CVE record for CVE-2026-8406 published?
Is CVE-2026-8406 actively exploited?
What is the CVSS score of CVE-2026-8406?
How do I remediate CVE-2026-8406?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-8406
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