CVE-2026-90820

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreHIGH confidence

Score 4.3 from GitHub Security Advisory published 2026-09-14. a secondary CVSS source baseline 4.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.3Exploit: None knownExposed: 0

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

A security vulnerability has been detected in a2aproject a2a-java 1.2.0. The impacted element is the function AuthorizationRequestHandlerDecorator.onListTasks of the file server-common/src/main/java/org/a2aproject/sdk/server/requesthandlers/AuthorizationRequestHandlerDecorator.java. Such manipulation leads to missing authorization. The attack can be launched remotely. Upgrading to version 1.3.0 is sufficient to resolve this issue. The name of the patch is e9a1abf9c90c02b16d17293afdc3cc2f555d63a6. The affected component should be upgraded.

CVSS v3
4.3
EG Score
4.3(high)
EG Risk
19(Track)
EG Risk 19/100SSVC: 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
Severity43% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
14%
KEV
Not listed

Published

September 14, 2026

Last Modified

September 15, 2026

Advisory Details (4)

Auto-updated Sep 14, 2026
Patch available. Sources: github_pr, github_commit, github_release.
generic

GitHub - a2aproject/a2a-java: Official Java SDK for the Agent2Agent (A2A) Protocol · GitHub

https://github.com/a2aproject/a2a-java/
github_release Patch Available

v1.3.0.Final

Patch available: a2aproject/a2a-java v1.3.0.Final

https://github.com/a2aproject/a2a-java/releases/tag/v1.3.0.Final
github_commit Patch Available

commit e9a1abf9c90c (a2aproject/a2a-java)

Patch available: a2aproject/a2a-java v1.3.0.Final (contains commit e9a1abf9c90c)

https://github.com/a2aproject/a2a-java/commit/e9a1abf9c90c02b16d17293afdc3cc2f555d63a6
github_pr Patch Available

fix(security): enforce authorization for listTasks

Patch available: a2aproject/a2a-java v1.3.0.Final (PR #1038 merged 2026-08-11)

https://github.com/a2aproject/a2a-java/pull/1038

Vendor Advisories for CVE-2026-90820(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 20× in last 7d / 20× 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. 2026-09-19 16:33 UTCEG score recompute
  2. 2026-09-19 16:33 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 16:14 UTCEG score recompute
  5. 2026-09-18 16:14 UTCGHSA enrichment
  6. 2026-09-17 19:32 UTCEPSS rescore
  7. 2026-09-17 15:54 UTCGHSA enrichment
  8. 2026-09-16 15:34 UTCEG score recompute
  9. 2026-09-16 15:34 UTCGHSA enrichment
  10. 2026-09-16 14:09 UTCEPSS rescore
  11. 2026-09-16 05:15 UTCEPSS rescore
  12. 2026-09-15 15:01 UTCGHSA enrichment
  13. 2026-09-15 14:34 UTCEG score recompute
  14. 2026-09-15 14:34 UTCGHSA enrichment
  15. 2026-09-15 14:03 UTCEG score recompute
  16. 2026-09-15 14:03 UTCGHSA enrichment
  17. 2026-09-14 21:32 UTCEG score recompute
  18. 2026-09-14 21:32 UTCGHSA enrichment
  19. 2026-09-14 20:49 UTCEG score recompute
  20. 2026-09-14 20:49 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-90820?
CVE-2026-90820 is a medium vulnerability published on September 14, 2026. A security vulnerability has been detected in a2aproject a2a-java 1.2.0. The impacted element is the function AuthorizationRequestHandlerDecorator.onListTasks of the file server-common/src/main/java/org/a2aproject/sdk/server/requesthandlers/AuthorizationRequestHandlerDecorator.java. Such…
When was CVE-2026-90820 disclosed?
CVE-2026-90820 was first published in the National Vulnerability Database on September 14, 2026, with the most recent update on September 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-90820 actively exploited?
CVE-2026-90820 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 85.7% of all scored CVEs.
What is the CVSS score of CVE-2026-90820?
CVE-2026-90820 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2026-90820?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-90820, 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-2026-90820

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