CVE-2026-86419

MISP Insufficient Outbound URL Validation Allows SSRF and Credential Disclosure via Feed Redirects and TAXII Discovery

Published Sep 7, 2026 CVSS 4.0 · 7 High EPSS < 1% KEV · Not listed
Description
Affected versions of MISP contain insufficient validation of server-side outbound HTTP destinations in feed retrieval and TAXII discovery functionality.


In feed processing, redirects were followed without validating the redirect scheme or destination. The original request headers were reused across redirect hops, meaning authentication headers or API credentials configured for a feed could be forwarded to a different host. Redirects could also target internal network resources, resulting in SSRF. The fix adds redirect validation, blocks internal destinations for cross-host redirects, strips configured feed credentials before following redirects to another host, and pins validated DNS results to prevent re-resolution after validation.


The TAXII discovery endpoint had a related incomplete SSRF defense. It used gethostbyname() and compared the result against only a few literal addresses. This missed cases including IPv6 loopback (::1), numeric host encodings such as 0x7f000001, and potentially multiple DNS records. The fix moves TAXII discovery to the shared URL egress validator.


Together, these commits harden MISP's outbound URL handling against alternate-address representations, DNS-related bypasses, unsafe redirects, internal-host access, and cross-host credential forwarding.






Version affected: ≤2.5.45

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Misp-project
Misp-project misp
CPEs cpe:2.3:a:misp-project:misp:*:*:*:*:*:*:*:*
Vendors & Products Misp-project
Misp-project misp
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Misp
Misp misp
Vendors & Products Misp
Misp misp
Type Values Removed Values Added
Description Affected versions of MISP contain insufficient validation of server-side outbound HTTP destinations in feed retrieval and TAXII discovery functionality. In feed processing, redirects were followed without validating the redirect scheme or destination. The original request headers were reused across redirect hops, meaning authentication headers or API credentials configured for a feed could be forwarded to a different host. Redirects could also target internal network resources, resulting in SSRF. The fix adds redirect validation, blocks internal destinations for cross-host redirects, strips configured feed credentials before following redirects to another host, and pins validated DNS results to prevent re-resolution after validation. The TAXII discovery endpoint had a related incomplete SSRF defense. It used gethostbyname() and compared the result against only a few literal addresses. This missed cases including IPv6 loopback (::1), numeric host encodings such as 0x7f000001, and potentially multiple DNS records. The fix moves TAXII discovery to the shared URL egress validator. Together, these commits harden MISP's outbound URL handling against alternate-address representations, DNS-related bypasses, unsafe redirects, internal-host access, and cross-host credential forwarding. Version affected: ≤2.5.45
Title MISP Insufficient Outbound URL Validation Allows SSRF and Credential Disclosure via Feed Redirects and TAXII Discovery
Weaknesses CWE-200
CWE-918
References
Metrics cvssV4_0

{'score': 7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:H/SC:H/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
CIRCL
Published
Updated
Sep 8, 2026, 2:51 PM
Reserved
Sep 7, 2026, 12:31 PM
Status
Analyzed
Published
Sep 7, 2026, 1:20 PM
Modified
Sep 9, 2026, 3:25 PM