CVE-2026-101099

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreHIGH confidence

Score 4.3 from GitHub Security Advisory published 2026-09-28. 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: 0.5%CVSS: 4.3Exploit: None knownExposed services: Not assessed

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

A vulnerability was detected in ag-ui-protocol ag-ui up to 2026-09-23. This affects an unknown part of the file SseParser.kt of the component Kotlin Community SDK. Performing a manipulation results in handling of exceptional conditions. The attack may be initiated remotely. The pull request to fix this issue awaits acceptance.

CVSS v3
4.3
EG Score
4.3MEDIUMhigh confidence
EG Risk
20
EG Risk 20/100CISA SSVC

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%
Exploitation1% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.5%
EPSS %ILE
41st
KEV
Not listed

CISA SSVCTrack at every mission impact level.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 28, 2026

Last Modified

October 1, 2026

Advisory Details (3)

Auto-updated Sep 28, 2026
No patch confirmed yet. Sources: github_pr.
generic

GitHub - ag-ui-protocol/ag-ui: AG-UI: the Agent-User Interaction Protocol. Bring Agents into Frontend Applications. · GitHub

https://github.com/ag-ui-protocol/ag-ui/
github_pr

fix(java): bound transport payloads and terminate decoder failures

Upstream fix in progress (PR #2657 · ag-ui-protocol/ag-ui, state=open)

https://github.com/ag-ui-protocol/ag-ui/pull/2657
generic

[BUG]: Kotlin community SDK: StackOverflowError escapes `catch(Exception)`; unbounded accumulators in several community SDKs · Issue #2442 · ag-ui-protocol/ag-ui · GitHub

https://github.com/ag-ui-protocol/ag-ui/issues/2442

Vendor Advisories for CVE-2026-101099(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 23× in last 7d / 23× 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. 2026-10-04 10:39 UTCEG score recompute
  2. 2026-10-04 10:39 UTCGHSA enrichment
  3. 2026-10-03 14:25 UTCEPSS rescore
  4. 2026-10-03 12:13 UTCEG score recompute
  5. 2026-10-03 12:13 UTCGHSA enrichment
  6. 2026-10-02 13:50 UTCEG score recompute
  7. 2026-10-02 13:50 UTCGHSA enrichment
  8. 2026-10-01 19:49 UTCEPSS rescore
  9. 2026-10-01 15:24 UTCEG score recompute
  10. 2026-10-01 15:24 UTCGHSA enrichment
  11. 2026-10-01 14:51 UTCEG score recompute
  12. 2026-10-01 14:51 UTCGHSA enrichment
  13. 2026-09-30 18:03 UTCEG score recompute
  14. 2026-09-30 18:02 UTCGHSA enrichment
  15. 2026-09-30 15:02 UTCEPSS rescore
  16. 2026-09-29 19:40 UTCEG score recompute
  17. 2026-09-29 19:39 UTCGHSA enrichment
  18. 2026-09-29 15:20 UTCEPSS rescore
  19. 2026-09-28 21:13 UTCEG score recompute
  20. 2026-09-28 21:13 UTCGHSA enrichment
  21. 2026-09-28 18:20 UTCEG score recompute
  22. 2026-09-28 17:27 UTCEG score recompute
  23. 2026-09-28 17:26 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-101099?
CVE-2026-101099 is a medium vulnerability published on September 28, 2026. A vulnerability was detected in ag-ui-protocol ag-ui up to 2026-09-23. This affects an unknown part of the file SseParser.kt of the component Kotlin Community SDK. Performing a manipulation results in handling of exceptional conditions. The attack may be initiated remotely. The pull request to fix…
When was CVE-2026-101099 disclosed?
CVE-2026-101099 was first published on September 28, 2026, with the most recent update on October 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-101099 actively exploited?
CVE-2026-101099 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (41st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-101099?
CVE-2026-101099 has a CVSS base score of 4.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-101099?
No fix for CVE-2026-101099 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-101099 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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