CVE-2026-1721

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Source

https://cve.org/CVERecord?id=CVE-2026-1721

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-1721.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-1721

Aliases

GHSA-cvhv-6xm6-c3v4

Published

2026-02-13T01:46:48Z

Modified

2026-08-12T03:51:35Z

Severity

6.2 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N CVSS Calculator

Summary

Reflected Cross-Site Scripting (XSS) vulnerability in AI Playground site

Details

Summary

A Reflected Cross-Site Scripting (XSS) vulnerability was discovered in the AI Playground's OAuth callback handler. The error_description query parameter was directly interpolated into an HTML script tag without proper escaping, allowing attackers to execute arbitrary JavaScript in the context of the victim's session.

Root cause

The OAuth callback handler in site/ai-playground/src/server.ts directly interpolated the authError value, sourced from the error_description query parameter, into an inline <script> tag.

Impact

An attacker could craft a malicious link that, when clicked by a victim, would:

Steal user chat message history - Access all LLM interactions stored in the user's session.
Access connected MCP Servers - Interact with any MCP servers connected to the victim's session (public or authenticated/private), potentially allowing the attacker to perform actions on the victim's behalf

Mitigation:

PR: https://github.com/cloudflare/agents/pull/841 https://github.com/cloudflare/agents/pull/841
Agents-sdk users should upgrade to agents@0.3.10
Developers using configureOAuthCallback with custom error handling in their own applications should ensure all user-controlled input is escaped before interpolation.

Database specific

{
    "cna_assigner": "cloudflare",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/1xxx/CVE-2026-1721.json"
}

References

Affected packages

Git / github.com/cloudflare/agents

Affected ranges

Type

GIT

Repo

https://github.com/cloudflare/agents

Events

Introduced

Fixed

069c584847b00db334840e4d158f2862ed504226

Database specific

Show details

{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "0.3.10"
        }
    ],
    "source": "AFFECTED_FIELD"
}

Affected versions

@cloudflare/agents@0.*

@cloudflare/agents@0.0.0

@cloudflare/agents@0.0.1

@cloudflare/agents@0.0.10

@cloudflare/agents@0.0.11

@cloudflare/agents@0.0.12

@cloudflare/agents@0.0.13

@cloudflare/agents@0.0.14

@cloudflare/agents@0.0.15

@cloudflare/agents@0.0.16

@cloudflare/agents@0.0.2

@cloudflare/agents@0.0.3

@cloudflare/agents@0.0.5

@cloudflare/agents@0.0.8

@cloudflare/agents@0.0.9

@cloudflare/ai-chat@0.*

@cloudflare/ai-chat@0.0.3

@cloudflare/ai-chat@0.0.4

@cloudflare/ai-chat@0.0.5

@cloudflare/codemode@0.*

@cloudflare/codemode@0.0.3

@cloudflare/codemode@0.0.4

@cloudflare/codemode@0.0.5

@cloudflare/codemode@0.0.6

agents-sdk@0.*

agents-sdk@0.0.18

agents-sdk@0.0.20

agents-sdk@0.0.21

agents-sdk@0.0.22

agents-sdk@0.0.23

agents-sdk@0.0.24

agents-sdk@0.0.25

agents-sdk@0.0.26

agents-sdk@0.0.28

agents-sdk@0.0.29

agents-sdk@0.0.31

agents-sdk@0.0.32

agents-sdk@0.0.33

agents-sdk@0.0.34

agents-sdk@0.0.35

agents-sdk@0.0.36

agents@0.*

agents@0.0.100

agents@0.0.101

agents@0.0.102

agents@0.0.103

agents@0.0.104

agents@0.0.105

agents@0.0.106

agents@0.0.107

agents@0.0.108

agents@0.0.109

agents@0.0.37

agents@0.0.38

agents@0.0.39

agents@0.0.40

agents@0.0.41

agents@0.0.42

agents@0.0.43

agents@0.0.44

agents@0.0.45

agents@0.0.46

agents@0.0.48

agents@0.0.49

agents@0.0.50

agents@0.0.51

agents@0.0.52

agents@0.0.53

agents@0.0.55

agents@0.0.56

agents@0.0.57

agents@0.0.58

agents@0.0.59

agents@0.0.60

agents@0.0.61

agents@0.0.62

agents@0.0.63

agents@0.0.64

agents@0.0.65

agents@0.0.66

agents@0.0.67

agents@0.0.68

agents@0.0.69

agents@0.0.70

agents@0.0.71

agents@0.0.72

agents@0.0.73

agents@0.0.74

agents@0.0.75

agents@0.0.76

agents@0.0.77

agents@0.0.85

agents@0.0.86

agents@0.0.87

agents@0.0.88

agents@0.0.89

agents@0.0.90

agents@0.0.91

agents@0.0.92

agents@0.0.93

agents@0.0.94

agents@0.0.95

agents@0.0.98

agents@0.0.99

agents@0.1.1

agents@0.1.2

agents@0.1.3

agents@0.1.4

agents@0.1.5

agents@0.1.6

agents@0.2.0

agents@0.2.1

agents@0.2.10

agents@0.2.11

agents@0.2.12

agents@0.2.13

agents@0.2.14

agents@0.2.15

agents@0.2.16

agents@0.2.17

agents@0.2.18

agents@0.2.19

agents@0.2.2

agents@0.2.20

agents@0.2.21

agents@0.2.22

agents@0.2.23

agents@0.2.24

agents@0.2.25

agents@0.2.26

agents@0.2.27

agents@0.2.28

agents@0.2.29

agents@0.2.3

agents@0.2.30

agents@0.2.31

agents@0.2.32

agents@0.2.34

agents@0.2.35

agents@0.2.4

agents@0.2.6

agents@0.2.7

agents@0.2.8

agents@0.2.9

agents@0.3.0

agents@0.3.1

agents@0.3.3

agents@0.3.4

agents@0.3.5

agents@0.3.6

agents@0.3.7

agents@0.3.8

agents@0.3.9

hono-agents@0.*

hono-agents@0.0.10

hono-agents@0.0.11

hono-agents@0.0.12

hono-agents@0.0.13

hono-agents@0.0.14

hono-agents@0.0.15

hono-agents@0.0.16

hono-agents@0.0.18

hono-agents@0.0.19

hono-agents@0.0.21

hono-agents@0.0.22

hono-agents@0.0.23

hono-agents@0.0.24

hono-agents@0.0.25

hono-agents@0.0.26

hono-agents@0.0.27

hono-agents@0.0.28

hono-agents@0.0.29

hono-agents@0.0.30

hono-agents@0.0.31

hono-agents@0.0.32

hono-agents@0.0.33

hono-agents@0.0.35

hono-agents@0.0.36

hono-agents@0.0.37

hono-agents@0.0.38

hono-agents@0.0.40

hono-agents@0.0.41

hono-agents@0.0.42

hono-agents@0.0.43

hono-agents@0.0.45

hono-agents@0.0.46

hono-agents@0.0.47

hono-agents@0.0.48

hono-agents@0.0.49

hono-agents@0.0.50

hono-agents@0.0.51

hono-agents@0.0.52

hono-agents@0.0.53

hono-agents@0.0.54

hono-agents@0.0.55

hono-agents@0.0.56

hono-agents@0.0.57

hono-agents@0.0.58

hono-agents@0.0.59

hono-agents@0.0.6

hono-agents@0.0.60

hono-agents@0.0.61

hono-agents@0.0.62

hono-agents@0.0.63

hono-agents@0.0.64

hono-agents@0.0.65

hono-agents@0.0.66

hono-agents@0.0.67

hono-agents@0.0.7

hono-agents@0.0.75

hono-agents@0.0.76

hono-agents@0.0.77

hono-agents@0.0.78

hono-agents@0.0.79

hono-agents@0.0.8

hono-agents@0.0.80

hono-agents@0.0.81

hono-agents@0.0.82

hono-agents@0.0.83

hono-agents@0.0.84

hono-agents@0.0.85

hono-agents@0.0.88

hono-agents@0.0.89

hono-agents@0.0.9

hono-agents@0.0.90

hono-agents@0.0.91

hono-agents@0.0.92

hono-agents@0.0.93

hono-agents@0.0.94

hono-agents@0.0.95

hono-agents@0.0.96

hono-agents@0.0.97

hono-agents@0.0.98

hono-agents@0.0.99

hono-agents@1.*

hono-agents@1.0.1

hono-agents@1.0.2

hono-agents@2.*

hono-agents@2.0.0

hono-agents@2.0.1

hono-agents@2.0.2

hono-agents@2.0.3

hono-agents@2.0.4

hono-agents@2.0.5

hono-agents@2.0.6

hono-agents@2.0.7

hono-agents@2.0.8

hono-agents@3.*

hono-agents@3.0.0

hono-agents@3.0.1

hono-agents@3.0.2

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-1721.json"