{ "document": { "category": "csaf_base", "csaf_version": "2.0", "distribution": { "tlp": { "label": "WHITE" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings." } ], "publisher": { "category": "coordinator", "contact_details": "cert@ncsc.nl", "name": "National Cyber Security Centre", "namespace": "https://www.ncsc.nl/" }, "title": "CVE-2026-30871", "tracking": { "current_release_date": "2026-03-25T04:39:34.396086Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-30871", "initial_release_date": "2026-03-20T18:20:12.606294Z", "revision_history": [ { "date": "2026-03-20T18:20:12.606294Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)." }, { "date": "2026-03-20T18:20:16.261350Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-03-20T18:20:51.021705Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (2).| References created (3).| CWES updated (1)." }, { "date": "2026-03-20T18:20:53.643272Z", "number": "4", "summary": "NCSC Score updated." }, { "date": "2026-03-20T18:23:11.174098Z", "number": "5", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (5).| CWES updated (1).| Vendor_assessment created." }, { "date": "2026-03-20T18:23:16.058946Z", "number": "6", "summary": "NCSC Score updated." }, { "date": "2026-03-20T20:39:24.916290Z", "number": "7", "summary": "Unknown change." }, { "date": "2026-03-20T22:03:06.596880Z", "number": "8", "summary": "Source connected.| CVE status created. (valid)| EPSS created." }, { "date": "2026-03-24T20:49:16.617643Z", "number": "9", "summary": "CVSS created.| Products connected (2).| Product Identifiers created (2)." }, { "date": "2026-03-24T20:49:22.033775Z", "number": "10", "summary": "NCSC Score updated." }, { "date": "2026-03-25T04:39:32.722238Z", "number": "11", "summary": "Unknown change." } ], "status": "interim", "version": "11" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<24.10.6", "product": { "name": "vers:unknown/<24.10.6", "product_id": "CSAFPID-5873998", "product_identification_helper": { "cpe": "cpe:2.3:o:openwrt:openwrt:*:*:*:*:*:*:*:*" } } }, { "category": "product_version_range", "name": "vers:unknown/>=25.12.0-rc1|<25.12.1", "product": { "name": "vers:unknown/>=25.12.0-rc1|<25.12.1", "product_id": "CSAFPID-5873997" } }, { "category": "product_version_range", "name": "vers:unknown/>=25.12.0|<25.12.1", "product": { "name": "vers:unknown/>=25.12.0|<25.12.1", "product_id": "CSAFPID-5874022", "product_identification_helper": { "cpe": "cpe:2.3:o:openwrt:openwrt:*:*:*:*:*:*:*:*" } } } ], "category": "product_name", "name": "openwrt" } ], "category": "vendor", "name": "OpenWrt" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-30871", "cwe": { "id": "CWE-121", "name": "Stack-based Buffer Overflow" }, "notes": [ { "category": "description", "text": "OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based Buffer Overflow vulnerability in the parse_question function. The issue is triggered by PTR queries for reverse DNS domains (.in-addr.arpa and .ip6.arpa). DNS packets received on UDP port 5353 are expanded by dn_expand into an 8096-byte global buffer (name_buffer), which is then copied via an unbounded strcpy into a fixed 256-byte stack buffer when handling TYPE_PTR queries. The overflow is possible because dn_expand converts non-printable ASCII bytes (e.g., 0x01) into multi-character octal representations (e.g., \\001), significantly inflating the expanded name beyond the stack buffer's capacity. A crafted DNS packet can exploit this expansion behavior to overflow the stack buffer, making the vulnerability reachable through normal multicast DNS packet processing. This issue has been fixed in versions 24.10.6 and 25.12.1.", "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-30871" }, { "category": "description", "text": "OpenWrt Project is a Linux operating system targeting embedded devices. In versions prior to 24.10.6 and 25.12.1, the mdns daemon has a Stack-based Buffer Overflow vulnerability in the parse_question function. The issue is triggered by PTR queries for reverse DNS domains (.in-addr.arpa and .ip6.arpa). DNS packets received on UDP port 5353 are expanded by dn_expand into an 8096-byte global buffer (name_buffer), which is then copied via an unbounded strcpy into a fixed 256-byte stack buffer when handling TYPE_PTR queries. The overflow is possible because dn_expand converts non-printable ASCII bytes (e.g., 0x01) into multi-character octal representations (e.g., \\001), significantly inflating the expanded name beyond the stack buffer's capacity. A crafted DNS packet can exploit this expansion behavior to overflow the stack buffer, making the vulnerability reachable through normal multicast DNS packet processing. This issue has been fixed in versions 24.10.6 and 25.12.1.", "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/30xxx/CVE-2026-30871.json" }, { "category": "description", "text": "A flaw was found in the OpenWrt mdns daemon. A remote attacker can exploit a Stack-based Buffer Overflow vulnerability in the `parse_question` function by sending specially crafted DNS (Domain Name System) packets. These packets, specifically PTR (Pointer Record) queries for reverse DNS domains, can cause the `dn_expand` function to inflate the size of the expanded name. This inflated name is then copied into a smaller fixed-size buffer using an unbounded copy operation, leading to a buffer overflow. This can result in arbitrary code execution or a denial of service (DoS) on the affected device.", "title": "redhat - https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-30871.json" }, { "category": "other", "text": "0.00012", "title": "EPSS" }, { "category": "other", "text": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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:X/R:X/V:X/RE:X/U:X", "title": "CVSSV4" }, { "category": "other", "text": "9.5", "title": "CVSSV4 base score" }, { "category": "other", "text": "4.9", "title": "NCSC Score" }, { "category": "other", "text": "Is related to (a version of) an uncommon product, There is cwe data available from source Nvd", "title": "NCSC Score top decreasing factors" }, { "category": "details", "text": "Severity: 4\n", "title": "Vendor assessment" } ], "product_status": { "known_affected": [ "CSAFPID-5873997", "CSAFPID-5873998", "CSAFPID-5874022" ] }, "references": [ { "category": "external", "summary": "Source - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-30871" }, { "category": "external", "summary": "Source - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/30xxx/CVE-2026-30871.json" }, { "category": "external", "summary": "Source - redhat", "url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-30871.json" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd; redhat", "url": "https://github.com/openwrt/openwrt/releases/tag/v24.10.6" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd; redhat", "url": "https://github.com/openwrt/openwrt/releases/tag/v25.12.1" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd; redhat", "url": "https://github.com/openwrt/openwrt/security/advisories/GHSA-7c3j-f7w2-p8f6" }, { "category": "external", "summary": "Reference - redhat", "url": "https://www.cve.org/CVERecord?id=CVE-2026-30871" }, { "category": "external", "summary": "Reference - redhat", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-30871" } ], "scores": [ { "cvss_v3": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "products": [ "CSAFPID-5873997", "CSAFPID-5873998", "CSAFPID-5874022" ] } ], "title": "CVE-2026-30871" } ] }