CVE-2026-77989

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 83% 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
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

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

Joomla Extension - joomlaeventmanager.net - Reflected XSS via the PDF export link in Joomla Events Manager < 5.0.1 - buildCurrentPdfLink copies the current request query string into the PDF button URL, and pdfbutton() echoes it unescaped, leading to an reflected XSS vector.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
39(Track)
EG Risk 39/100SSVC: 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
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
17%
KEV
Not listed

Published

August 27, 2026

Last Modified

August 28, 2026

Advisory Details (1)

Auto-updated Aug 27, 2026
No patch confirmed yet.
generic

JEM - Joomla Event Manager

https://www.joomlaeventmanager.net/

Vendor Advisories for CVE-2026-77989(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 17× in last 7d / 17× 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. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 17:41 UTCEG score recompute
  3. 2026-08-29 17:41 UTCGHSA enrichment
  4. 2026-08-28 21:42 UTCEPSS rescore
  5. 2026-08-28 16:14 UTCEG score recompute
  6. 2026-08-28 16:14 UTCGHSA enrichment
  7. 2026-08-28 11:27 UTCEG score recompute
  8. 2026-08-28 11:27 UTCGHSA enrichment
  9. 2026-08-27 17:28 UTCEG score recompute
  10. 2026-08-27 17:28 UTCGHSA enrichment
  11. 2026-08-27 17:03 UTCEG score recompute
  12. 2026-08-27 17:03 UTCGHSA enrichment
  13. 2026-08-27 14:25 UTCEPSS rescore
  14. 2026-08-27 06:35 UTCEG score recompute
  15. 2026-08-27 06:34 UTCGHSA enrichment
  16. 2026-08-27 06:13 UTCEG score recompute
  17. 2026-08-27 06:11 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-77989?
CVE-2026-77989 is a medium vulnerability published on August 27, 2026. Joomla Extension - joomlaeventmanager.net - Reflected XSS via the PDF export link in Joomla Events Manager < 5.0.1 - buildCurrentPdfLink copies the current request query string into the PDF button URL, and pdfbutton() echoes it unescaped, leading to an reflected XSS vector.
When was CVE-2026-77989 disclosed?
CVE-2026-77989 was first published in the National Vulnerability Database on August 27, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77989 actively exploited?
CVE-2026-77989 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 82.8% of all scored CVEs.
What is the CVSS score of CVE-2026-77989?
CVE-2026-77989 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-77989?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77989, 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-2026-77989

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