CVE-2026-15389

HIGHPre-NVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 81% 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
Trending — 4 sources updated this week
8.7
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.7Exploit: NoneExposed: 0

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

A vulnerability relating to insufficient access control has been identified in the session management of the Sesame Time web application and its REST v3 API. The flaw lies in the fact that the system uses the session identifier (USID) as the sole validation mechanism, without verifying whether that identifier legitimately belongs to the user making the request. As a result, an attacker who obtains a valid USID can impersonate a victim’s session and access their confidential information, including emails, user IDs, roles and corporate data. This vulnerability is exacerbated by poor session lifecycle management: new logins generate additional USIDs without revoking the previous ones, allowing multiple active sessions to coexist and thereby expanding the attack surface.

CVSS v3
8.7
EG Score
8.7(medium)
EPSS
19.4%
KEV
Not listed

Published

July 14, 2026

Last Modified

July 15, 2026

Advisory Details (1)

Auto-updated Jul 14, 2026
No patch confirmed yet.
generic

Inadequate access control in Sesame Time session management | INCIBE-CERT | INCIBE

https://www.incibe.es/en/incibe-cert/notices/aviso/inadequate-access-control-sesame-time-session-management

Vendor Advisories for CVE-2026-15389(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 / 9× 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.

  1. 2026-07-15 22:51 UTCEG score recompute
  2. 2026-07-15 22:51 UTCGHSA enrichment
  3. 2026-07-15 16:57 UTCEPSS rescore
  4. 2026-07-15 10:44 UTCEG score recompute
  5. 2026-07-15 10:44 UTCGHSA enrichment
  6. 2026-07-14 22:36 UTCEG score recompute
  7. 2026-07-14 22:36 UTCGHSA enrichment
  8. 2026-07-14 10:30 UTCEG score recompute
  9. 2026-07-14 10:30 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-15389?
CVE-2026-15389 is a high vulnerability published on July 14, 2026. A vulnerability relating to insufficient access control has been identified in the session management of the Sesame Time web application and its REST v3 API. The flaw lies in the fact that the system uses the session identifier (USID) as the sole validation mechanism, without verifying whether that…
When was CVE-2026-15389 disclosed?
CVE-2026-15389 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-15389 actively exploited?
CVE-2026-15389 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 19.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-15389?
CVE-2026-15389 has a CVSS v3 base score of 8.7 (NVD).
How do I remediate CVE-2026-15389?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-15389, 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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