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CVE-2026-112991

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cve id
CVE-2026-112991
published
2026-10-19T23:17:36.350
last modified
2026-10-19T23:17:36.350
status
Received
description
The html_to_markdown expansion module in MISP Modules contains a server-side request forgery (SSRF) vulnerability in its is_safe_url() URL validation function. The BLOCKED_RANGES list used to reject unsafe destination addresses was incomplete, omitting several critical IP address ranges. Specifically, the following ranges were not blocked: 0.0.0.0/8 (unspecified, which routes to loopback on Linux), 100.64.0.0/10 (carrier-grade NAT per RFC 6598), ::/128 (IPv6 unspecified), fc00::/7 (IPv6 Unique Local Addresses), and fe80::/10 (IPv6 link-local). The existing list only covered IPv4 loopback (127.0.0.0/8), RFC 1918 private ranges, IPv4 link-local (169.254.0.0/16), and IPv6 loopback (::1/128). An authenticated user with the ability to create or modify MISP attributes that trigger the html_to_markdown expansion module could supply URLs pointing to these unblocked internal address ranges. Because the module fetches the URL server-side to convert HTML content to Markdown, the request is made from the MISP server's network context. This allows an attacker to probe and read responses from internal services, carrier-grade NAT infrastructure, or link-local endpoints that would otherwise be un
cvss score
—
cvss severity
—
cvss vector
—
cwes
CWE-20|CWE-918
cpe count
0
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Cite this record

CVE-2026-112991 — CVE. NIST, via Voidly Atlas — Surveillance & Digital-Rights Watch. Retrieved 2026-10-20, https://voidly.ai/atlas/federal/nvd-cves/CVE-2026-112991

@misc{voidly_nvd_cves_CVE2026112991,
  title        = {CVE-2026-112991 — CVE},
  author       = {{Voidly}},
  howpublished = {\url{https://voidly.ai/atlas/federal/nvd-cves/CVE-2026-112991}},
  note         = {Source: NIST National Vulnerability Database, https://nvd.nist.gov/vuln/detail/CVE-2026-112991. Public domain (17 U.S.C. §105); re-surfaced under CC BY 4.0},
  urldate      = {2026-10-20},
  year         = {2026}
}

Also available as JSON/BibTeX/APA: API record. Source data is U.S. federal public domain (17 U.S.C. §105). Re-surfaced by Voidly under CC BY 4.0.