ag-ui-protocol ag-ui SSE Parser sse.ts parseSSEStream resource consumption
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 13/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fix or patch referenced
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The ag-ui-protocol ag-ui TypeScript client library, specifically its server-sent events (SSE) stream parser, is affected. A remote attacker could craft malicious event stream input that causes excessive resource consumption, potentially degrading or disrupting the application that uses the parser.
Read the original description
A security vulnerability has been detected in ag-ui-protocol ag-ui up to 0.0.58. Affected is the function parseSSEStream of the file sdks/typescript/packages/client/src/transform/sse.ts of the component SSE Parser. The manipulation leads to resource consumption. The attack may be initiated remotely. The exploit has been disclosed publicly and may be used. The identifier of the patch is 9e7b2b00bce215bbf731f1e6094f63812527c432. The affected component should be upgraded.
What to do
Check whether your setup matches what the bug needs.
Uses the TypeScript client @ag-ui/client, verified against npm release 0.0.58 The client receives a streamed response that never emits a message boundary (SSE) or leaves a protobuf length prefix unsatisfiedApply the patch listed under Evidence.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- ag-ui-protocol ag-ui
0.0.1, 0.0.2, 0.0.3, 0.0.4, 0.0.5, 0.0.6, 0.0.7, 0.0.8, 0.0.9, 0.0.10, 0.0.11, 0.0.12, 0.0.13, 0.0.14, 0.0.15, 0.0.16, 0.0.17, 0.0.18, 0.0.19, 0.0.20, 0.0.21, 0.0.22, 0.0.23, 0.0.24, 0.0.25, 0.0.26, 0.0.27, 0.0.28, 0.0.29, 0.0.30, and 28 more
Evidence 9
- Advisory
- Advisory
- Advisory
- Advisory
- Patch
- Patch
- Patch
- Exploit
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-120235
What does this mean?
The SSE parser in the ag-ui TypeScript client keeps buffering a streamed response while it waits for a message boundary. If the server never sends one, the buffer keeps growing to the size of the response, which can use up client memory.Source: github.com
Am I affected, and how do I check?
The advisory verified this against the @ag-ui/client npm release 0.0.58. To check your setup, look up the installed @ag-ui/client version in your package manifest or lockfile, and note whether the client reads streamed responses through the SSE or protobuf parser.Source: github.com
What should I do about it?
No fixed release is listed in the checked facts, so no upgrade target is given. Check the project's advisory or release notes for a fixed version before changing dependencies.Source: github.com
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data