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Fencer Vulns
medium 4.3

CVE-2026-120235 json

ag-ui-protocol ag-ui SSE Parser sse.ts parseSSEStream resource consumption

published 2026-11-01 7 d ago modified 2026-11-02 6 d ago also EUVD-2026-114864

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 29%
public exploits
0
none known

Summary

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.

Patch / fix

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
6 d ago

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/ag-ui-protocol/ag-ui/issues/2522 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C
CNA 3.0 4.3 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C
CNA 2.0 4.0 AV:N/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:OF/RC:C
CNA 4.0 2.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CNA 2.0 4.0 AV:N/AC:L/Au:S/C:N/I:N/A:P

Affected products

  • ag-ui-protocol ag-ui

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-404 Improper Resource Shutdown or Release

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.