CVE-2026-112991
Medium · CVSS 6.3Published 2026-10-19
CVSS
6.3
Medium
EPSS
—
exploit probability
Active Exploit
No
not yet listed
What is CVE-2026-112991?
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 unreachable from external networks. IPv4-mapped IPv6 forms (e.g., [::ffff:0.0.0.0]) also bypassed the existing checks. The security impact is primarily confidentiality: an attacker can read data served by internal services reachable from the MISP server. The MISP instance itself is not compromised, but it is abused as a proxy to access otherwise restricted network resources.
CVSS Score Explained
CVSS 6.3 is Medium severity. Exploitation usually requires some specific conditions (local access, user interaction, or a particular config). Still worth patching in your next maintenance window.
EPSS Exploitation Probability
No EPSS score yet — model needs more data on this CVE.
References & Patches
Track vulnerabilities for your stack
Tell us what tech you run — Node.js, Python, Java, nginx, whatever — and get a weekly email when new CVEs affect it.
Recent CVEs
- CVE-2026-112027A vulnerability was detected in light0011 cms c774dce31c6df0055568a8d5c53d964d99be199d/f72cf46f601efb2a0618c3814cc2f61380b38930. Affected by this vulnerability is the function file_exists of the file Public/Home/js/uploadify/check-exists.php of the component Uploadify. The manipulation of the argument filename results in file and directory information exposure. The attack may be launched remotely. The exploit is now public and may be used. The project was informed of the problem early through an issue report but has not responded yet.5.5
- CVE-2026-112028A flaw has been found in light0011 cms c774dce31c6df0055568a8d5c53d964d99be199d/f72cf46f601efb2a0618c3814cc2f61380b38930. Affected by this issue is some unknown functionality of the file App/Home/Controller/VoteController.class.php of the component Vote Handler. This manipulation of the argument X-Requested-With causes business logic errors. Remote exploitation of the attack is possible. The exploit has been published and may be used. The project was informed of the problem early through an issue report but has not responded yet.5.5
- CVE-2026-112029A vulnerability has been found in diem-project diem up to 5.1.3. This affects an unknown part of the file lib/model/doctrine/PluginDmUser.class.php of the component SHA1 Handler. Such manipulation of the argument salt/password leads to password hash with insufficient computational effort. The attack needs to be performed locally. The attack requires a high level of complexity. It is indicated that the exploitability is difficult. The exploit has been disclosed to the public and may be used. The project was informed of the problem early through an issue report but has not responded yet.1.1
- CVE-2026-112111The Bootstrap Shortcodes plugin for WordPress before 3.4.6 is vulnerable to stored XSS via the id attribute of the [bs_tcontent] shortcode. The bs_tcontent() shortcode handler in inc/bs_tabs.php emits the id attribute value into an unquoted HTML attribute. esc_attr() is applied, but it does not encode space characters, so a space in the supplied value terminates the attribute and any following text is parsed as additional HTML attributes, including JavaScript event handlers. This allows authenticated attackers with Contributor-level access and above to inject arbitrary web script that executes in the browser of any user who views the page and interacts with the injected element.5.1
- CVE-2026-112112An IPv6 FlowSpec validation bypass in the CZ.NIC BIRD Internet Routing Daemon allows an established BGP peer to inject FlowSpec rules matching destinations outside the address space authorized by the unicast-route validation procedure. With validation enabled on the receiving flow6 channel, BIRD fails to reject a destination prefix component with a nonzero offset, contrary to RFC 8956 section 5. It validates a reconstructed prefix with zero-filled skipped bits, although the original FlowSpec component can match a broader set of IPv6 addresses. Given a suitable unicast route from the peer, the rule can pass validation and, where export policy permits, be propagated to downstream peers. Downstream enforcement may cause unauthorized traffic filtering or redirection.2.3
- CVE-2026-108519Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.—