{ "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-2026-35091", "tracking": { "current_release_date": "2026-04-02T15:01:02.777376Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-35091", "initial_release_date": "2026-04-01T13:39:01.781111Z", "revision_history": [ { "date": "2026-04-01T13:39:01.781111Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)." }, { "date": "2026-04-01T13:39:04.079792Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-04-01T14:44:41.431456Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)." }, { "date": "2026-04-01T14:44:51.944828Z", "number": "4", "summary": "NCSC Score updated." }, { "date": "2026-04-01T15:51:39.128404Z", "number": "5", "summary": "NCSC Score updated." }, { "date": "2026-04-01T21:38:46.580730Z", "number": "6", "summary": "Unknown change." }, { "date": "2026-04-02T00:29:01.855592Z", "number": "7", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (7).| Product Identifiers created (5).| Product Remediations created (10).| Products created (3).| References created (3).| CWES updated (1).| Vendor_assessment created." }, { "date": "2026-04-02T00:29:04.516212Z", "number": "8", "summary": "NCSC Score updated." }, { "date": "2026-04-02T06:43:07.977925Z", "number": "9", "summary": "Source created.| CVE status created. (valid)| Description created for source.| Products connected (2)." }, { "date": "2026-04-02T06:43:10.039343Z", "number": "10", "summary": "NCSC Score updated." }, { "date": "2026-04-02T14:58:45.172102Z", "number": "11", "summary": "Source connected.| CVE status created. (valid)| EPSS created." }, { "date": "2026-04-02T14:58:53.341154Z", "number": "12", "summary": "NCSC Score updated." } ], "status": "interim", "version": "12" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/10", "product": { "name": "vers:rpm/10", "product_id": "CSAFPID-2858634", "product_identification_helper": { "cpe": "cpe:/o:redhat:enterprise_linux:10" } } } ], "category": "product_name", "name": "Red Hat Enterprise Linux 10" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/7", "product": { "name": "vers:rpm/7", "product_id": "CSAFPID-1439315", "product_identification_helper": { "cpe": "cpe:/o:redhat:enterprise_linux:7" } } } ], "category": "product_name", "name": "Red Hat Enterprise Linux 7" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/8", "product": { "name": "vers:rpm/8", "product_id": "CSAFPID-1439317", "product_identification_helper": { "cpe": "cpe:/o:redhat:enterprise_linux:8" } } } ], "category": "product_name", "name": "Red Hat Enterprise Linux 8" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/9", "product": { "name": "vers:rpm/9", "product_id": "CSAFPID-1439319", "product_identification_helper": { "cpe": "cpe:/a:redhat:enterprise_linux:9" } } } ], "category": "product_name", "name": "Red Hat Enterprise Linux 9" }, { "branches": [ { "category": "product_version_range", "name": "vers:rpm/4", "product": { "name": "vers:rpm/4", "product_id": "CSAFPID-1439328", "product_identification_helper": { "cpe": "cpe:/a:redhat:openshift:4" } } } ], "category": "product_name", "name": "Red Hat OpenShift Container Platform 4" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-5983115" } } ], "category": "product_name", "name": "corosync" } ], "category": "product_family", "name": "Red Hat Enterprise Linux 10" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-5983116" } } ], "category": "product_name", "name": "corosync" } ], "category": "product_family", "name": "Red Hat Enterprise Linux 7" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-5983117" } } ], "category": "product_name", "name": "corosync" } ], "category": "product_family", "name": "Red Hat Enterprise Linux 8" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-2557133" } } ], "category": "product_name", "name": "corosync" } ], "category": "product_family", "name": "Red Hat Enterprise Linux 9" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-1439329" } } ], "category": "product_name", "name": "rhcos" } ], "category": "product_family", "name": "Red Hat OpenShift Container Platform 4" } ], "category": "vendor", "name": "Red Hat" }, { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:deb/unknown", "product": { "name": "vers:deb/unknown", "product_id": "CSAFPID-2547683" } } ], "category": "product_name", "name": "corosync" } ], "category": "product_family", "name": "bookworm" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:deb/unknown", "product": { "name": "vers:deb/unknown", "product_id": "CSAFPID-2547684" } } ], "category": "product_name", "name": "corosync" } ], "category": "product_family", "name": "bullseye" } ], "category": "vendor", "name": "Debian" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-35091", "cwe": { "id": "CWE-253", "name": "Incorrect Check of Function Return Value" }, "notes": [ { "category": "description", "text": "A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token sanity check by sending a specially crafted User Datagram Protocol (UDP) packet. This can lead to an out-of-bounds read, causing a denial of service (DoS) and potentially disclosing limited memory contents. This vulnerability affects Corosync when running in totemudp/totemudpu mode, which is the default configuration.", "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/35xxx/CVE-2026-35091.json" }, { "category": "description", "text": "A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token sanity check by sending a specially crafted User Datagram Protocol (UDP) packet. This can lead to an out-of-bounds read, causing a denial of service (DoS) and potentially disclosing limited memory contents. This vulnerability affects Corosync when running in totemudp/totemudpu mode, which is the default configuration.", "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-35091" }, { "category": "description", "text": "A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token sanity check by sending a specially crafted User Datagram Protocol (UDP) packet. This can lead to an out-of-bounds read, causing a denial of service (DoS) and potentially disclosing limited memory contents. This vulnerability affects Corosync when running in totemudp/totemudpu mode, which is the default configuration.\nImportant: A wrong return value vulnerability in Corosync's membership commit token sanity check allows remote unauthenticated attackers to send a crafted UDP packet, leading to an out-of-bounds read and denial of service. This affects Corosync when running in totemudp/totemudpu mode, which is the default configuration.", "title": "redhat - https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-35091.json" }, { "category": "description", "text": "A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token sanity check by sending a specially crafted User Datagram Protocol (UDP) packet. This can lead to an out-of-bounds read, causing a denial of service (DoS) and potentially disclosing limited memory contents. This vulnerability affects Corosync when running in totemudp/totemudpu mode, which is the default configuration.", "title": "debian - https://security-tracker.debian.org/tracker/CVE-2026-35091" }, { "category": "other", "text": "0.00078", "title": "EPSS" }, { "category": "other", "text": "3.7", "title": "NCSC Score" }, { "category": "other", "text": "There is product_remediation data available from source Redhat, There is cwe data available from source Nvd, The value of the most recent EPSS score, There is product data available from source Debian", "title": "NCSC Score top decreasing factors" }, { "category": "details", "text": "Severity: 3\n", "title": "Vendor assessment" } ], "product_status": { "known_affected": [ "CSAFPID-1439315", "CSAFPID-1439317", "CSAFPID-1439319", "CSAFPID-1439328", "CSAFPID-1439329", "CSAFPID-2557133", "CSAFPID-2858634", "CSAFPID-5983115", "CSAFPID-5983116", "CSAFPID-5983117", "CSAFPID-2547683", "CSAFPID-2547684" ] }, "references": [ { "category": "external", "summary": "Source - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/35xxx/CVE-2026-35091.json" }, { "category": "external", "summary": "Source - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-35091" }, { "category": "external", "summary": "Source - redhat", "url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-35091.json" }, { "category": "external", "summary": "Source - debian", "url": "https://security-tracker.debian.org/tracker/CVE-2026-35091" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://access.redhat.com/security/cve/CVE-2026-35091" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd; redhat", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2453169" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2453813" }, { "category": "external", "summary": "Reference - redhat", "url": "https://www.cve.org/CVERecord?id=CVE-2026-35091" }, { "category": "external", "summary": "Reference - redhat", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-35091" } ], "remediations": [ { "category": "mitigation", "details": "To mitigate this vulnerability, restrict network access to the Corosync service on UDP port 5405 to only trusted hosts or networks. If Corosync is not required, consider disabling the service.\nExample firewall rule to restrict access to a trusted network (replace with your network):\n`firewall-cmd --permanent --add-rich-rule='rule family=\"ipv4\" port port=\"5405\" protocol=\"udp\" source address=\"\" accept'`\n`firewall-cmd --reload`\nTo disable the Corosync service:\n`systemctl stop corosync`\n`systemctl disable corosync`\nNote that restricting access may impact cluster communication, and disabling the service will prevent cluster operation. A restart of the Corosync service or a system reboot may be required for changes to take full effect.", "product_ids": [ "CSAFPID-1439315", "CSAFPID-1439317", "CSAFPID-1439319", "CSAFPID-1439328", "CSAFPID-1439329", "CSAFPID-2557133", "CSAFPID-2858634", "CSAFPID-5983115", "CSAFPID-5983116", "CSAFPID-5983117" ] } ], "scores": [ { "cvss_v3": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H", "baseScore": 8.2, "baseSeverity": "HIGH" }, "products": [ "CSAFPID-1439315", "CSAFPID-1439317", "CSAFPID-1439319", "CSAFPID-1439328", "CSAFPID-1439329", "CSAFPID-2547683", "CSAFPID-2547684", "CSAFPID-2557133", "CSAFPID-2858634", "CSAFPID-5983115", "CSAFPID-5983116", "CSAFPID-5983117" ] } ], "title": "CVE-2026-35091" } ] }