Server-Side Request Forgery protection bypass in misp-modules html_to_markdown via IPv4-mapped IPv6 addresses
Summary
| CVE | CVE-2026-62143 |
|---|---|
| State | PUBLISHED |
| Assigner | CIRCL |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-13 09:16:24 UTC |
| Updated | 2026-07-13 09:16:24 UTC |
| Description | A Server-Side Request Forgery (SSRF) protection bypass existed in the html_to_markdown expansion module of misp-modules. The module attempts to prevent requests to loopback, private, link-local, and other restricted IP address ranges. However, IP addresses were compared against the blocked ranges without first normalising IPv4-mapped IPv6 addresses. An authenticated attacker able to invoke the module could supply an IPv4-mapped IPv6 address, such as: http://[::ffff:127.0.0.1]/ http://[::ffff:169.254.169.254]/ Alternatively, the attacker could use a hostname that resolves to an IPv4-mapped IPv6 address. These addresses were treated as IPv6 addresses and therefore did not match the corresponding blocked IPv4 ranges. Successful exploitation could cause the misp-modules server to connect to services available through its loopback interface, internal network, or link-local network. This could expose internal web services, administrative interfaces, or cloud instance metadata, with retrieved content potentially returned to the attacker as converted Markdown. The vulnerability has been addressed by normalising IPv4-mapped IPv6 addresses to their underlying IPv4 representation before applying the blocked-range checks. URLs without a valid hostname are now also rejected. |
Risk And Classification
Primary CVSS: v4.0 8.3 HIGH from 5a6e4751-2f3f-4070-9419-94fb35b644e8
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/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:Y/R:X/V:X/RE:M/U:Green
Problem Types: CWE-918 | CWE-918 CWE-918 Server-Side Request Forgery (SSRF)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | Secondary | 8.3 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 8.3 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/AU:Y/... |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
LowUser Interaction
NoneConfidentiality
HighIntegrity
NoneAvailability
NoneSub Conf.
HighSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/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:Y/R:X/V:X/RE:M/U:Green
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Misp | Misp-modules | affected v3.0.8 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/MISP/misp-modules/commit/3bae4108a3ba1e507727d5264697fd7303ba... | 5a6e4751-2f3f-4070-9419-94fb35b644e8 | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Alexandre Dulaunoy (en)
CNA: George Chen (en)
There are currently no legacy QID mappings associated with this CVE.