ag-ui-protocol ag-ui Middleware filter-tool-calls.ts FilterToolCallsMiddleware cleanup
A flaw has been found in ag-ui-protocol ag-ui up to 2026-09-07. This vulnerability affects the function FilterToolCallsMiddleware of the file sdks/typescript/packages/client/src/middleware/filter-tool-calls.ts of the component Middleware. Executing a manipulation can lead to incomplete cleanup. The attack may be launched remotely. Upgrading to version 2026-09-08 is able to resolve this issue. This patch is called c346119fe870b70f5c19738ee5119f3e1456e59d. It is suggested to upgrade the affected component.
- Published
- Sep 28, 2026
- Updated
- Sep 28, 2026
- EPSS
- 0.3% · 21th percentile
- CWE
- CWE-459
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · VulDB
- 5.3
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulDB). Independent of NVD's CPE analysis and usually ahead of it.
ag-ui-protocol ag-ui
- 2026-09-08not affected
- 2026-09-07affected
Same product
ag-ui-protocol: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-92362ag-ui-protocol ag-ui SSE Frame sse.rs resource consumption27Monitor
- CVE-2026-101101ag-ui-protocol ag-ui Middleware convert.ts JSON.parse uncaught exception21Monitor
- CVE-2026-101099ag-ui-protocol ag-ui Kotlin Community SDK SseParser.kt exceptional condition21Monitor
- CVE-2026-101098ag-ui-protocol ag-ui HTTP JdkAgentHttpHandler.java readAllBytes resource consumption21Monitor
- CVE-2026-92361ag-ui-protocol ag-ui SSE Client client.go resource consumption21Monitor
- CVE-2026-92363ag-ui-protocol ag-ui JSON sse_parser.cpp resource consumption21Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| ag-ui-protocol ag-ui | 2026-09-08 · description | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- Fix recordedsame day
- TodayOct 9, 2026+11 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- meraklbz (VulDB User)reporter
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-459 · Incomplete CleanupCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
- SSVC exploitation— → none
For records you follow, these changes also arrive as notifications. →
References
- github.com/ag-ui-protocol/ag-ui/
- github.com/ag-ui-protocol/ag-ui/commit/c346119fe870b70f5c19738ee5119f3e1456e59d
- github.com/ag-ui-protocol/ag-ui/issues/2443
- github.com/ag-ui-protocol/ag-ui/pull/2494
- github.com/ag-ui-protocol/ag-ui/releases/tag/release/2026-09-08
- vuldb.com/cve/CVE-2026-101100
- vuldb.com/submit/934980
- vuldb.com/vuln/410975
- vuldb.com/vuln/410975/cti
Vendor advisories and official records. Exploit/PoC links are deliberately left out.