{
    "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-2026-34219",
        "tracking": {
            "current_release_date": "2026-04-01T15:13:08.405156Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-34219",
            "initial_release_date": "2026-03-30T13:41:46.538852Z",
            "revision_history": [
                {
                    "date": "2026-03-30T13:41:46.538852Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)."
                },
                {
                    "date": "2026-03-30T13:41:55.588503Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-31T07:35:30.641501Z",
                    "number": "3",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-31T16:25:36.083256Z",
                    "number": "4",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-31T16:25:38.017548Z",
                    "number": "5",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-31T16:39:34.220427Z",
                    "number": "6",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-31T16:39:41.224074Z",
                    "number": "7",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-31T18:39:07.153648Z",
                    "number": "8",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-03-31T19:55:21.742435Z",
                    "number": "9",
                    "summary": "References created (1)."
                },
                {
                    "date": "2026-04-01T15:13:02.641421Z",
                    "number": "10",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-04-01T15:13:07.064303Z",
                    "number": "11",
                    "summary": "NCSC Score updated."
                }
            ],
            "status": "interim",
            "version": "11"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<0.49.4",
                                "product": {
                                    "name": "vers:unknown/<0.49.4",
                                    "product_id": "CSAFPID-5969089"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "rust-libp2p"
                    }
                ],
                "category": "vendor",
                "name": "libp2p"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-34219",
            "cwe": {
                "id": "CWE-190",
                "name": "Integer Overflow or Wraparound"
            },
            "notes": [
                {
                    "category": "description",
                    "text": "## Description\n### Summary\nThe Rust libp2p Gossipsub implementation contains a remotely reachable panic in `backoff` expiry handling.  \nAfter a peer sends a crafted `PRUNE` control message with an attacker-controlled, near-maximum `backoff` value, the value is accepted and stored as an `Instant` near the representable upper bound. On a later heartbeat, the implementation performs unchecked `Instant + Duration` arithmetic (`backoff_time + slack`), which can overflow and panic with:\n`overflow when adding duration to instant`\nThis issue is reachable from any Gossipsub peer over normal `TCP + Noise + mplex/yamux` connectivity and requires no further authentication beyond becoming a protocol peer.\n### Attack Scenario\nAn attacker that can establish a libp2p Gossipsub session with a target node can crash the target by sending crafted `PRUNE` control data:\n1. Establish a standard libp2p session (`TCP + Noise`) and negotiate a stream multiplexer (`mplex`/`yamux`).\n2. Open a Gossipsub stream and send an RPC containing `ControlPrune` with a very large `backoff` (chosen near boundary conditions, e.g. `~ i64::MAX - victim_uptime_seconds`; example observed: `9223372036854674580` for ~28h uptime).\n3. The value is parsed from protobuf and passed through `Behaviour::handle_prune()` into mesh/backoff update logic.\n4. Initial storage path uses checked addition (`Instant::now().checked_add(...)`), so the malicious near-max value is retained.\n5. On the next heartbeat (typically within ~43–74s), expiry logic computes `backoff_time + slack` using unchecked addition, which overflows and panics.\n### Impact\nRemote unauthenticated denial of service (critical).  \nAny application exposing an affected `libp2p-gossipsub` listener can be crashed by a network-reachable peer that sends crafted `PRUNE` backoff values. The crash is triggered during heartbeat processing (not immediately at PRUNE parse time), and can be repeated by reconnecting and replaying the message.\n\n### Differences from CVE-2026-33040\nThis advisory is related to CVE-2026-33040 but it is not the same defect. CVE-2026-33040 addressed overflow during backoff insertion by adding checked arithmetic when converting PRUNE backoff into an Instant. The issue in this advisory occurs at a different location and at a different time: a near-maximum backoff can still be stored successfully, and the crash happens later in the heartbeat path when slack is added to that stored Instant using unchecked arithmetic.  This report covers a distinct secondary overflow path in heartbeat expiry handling that remained reachable after the original insertion-side hardening.\n\nThis vulnerability was originally reported by the Security team of the Ethereum Foundation.",
                    "title": "github - https://api.github.com/advisories/GHSA-xqmp-fxgv-xvq5"
                },
                {
                    "category": "description",
                    "text": "libp2p-rust is the official rust language Implementation of the libp2p networking stack. Prior to version 0.49.4, the Rust libp2p Gossipsub implementation contains a remotely reachable panic in backoff expiry handling. After a peer sends a crafted PRUNE control message with an attacker-controlled, near-maximum backoff value, the value is accepted and stored as an Instant near the representable upper bound. On a later heartbeat, the implementation performs unchecked Instant + Duration arithmetic (backoff_time + slack), which can overflow and panic with: overflow when adding duration to instant. This issue is reachable from any Gossipsub peer over normal TCP + Noise + mplex/yamux connectivity and requires no further authentication beyond becoming a protocol peer. This issue has been patched in version 0.49.4.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34219"
                },
                {
                    "category": "description",
                    "text": "libp2p-rust is the official rust language Implementation of the libp2p networking stack. Prior to version 0.49.4, the Rust libp2p Gossipsub implementation contains a remotely reachable panic in backoff expiry handling. After a peer sends a crafted PRUNE control message with an attacker-controlled, near-maximum backoff value, the value is accepted and stored as an Instant near the representable upper bound. On a later heartbeat, the implementation performs unchecked Instant + Duration arithmetic (backoff_time + slack), which can overflow and panic with: overflow when adding duration to instant. This issue is reachable from any Gossipsub peer over normal TCP + Noise + mplex/yamux connectivity and requires no further authentication beyond becoming a protocol peer. This issue has been patched in version 0.49.4.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34219.json"
                },
                {
                    "category": "other",
                    "text": "0.0005",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
                    "title": "CVSSV4"
                },
                {
                    "category": "other",
                    "text": "8.2",
                    "title": "CVSSV4 base score"
                },
                {
                    "category": "other",
                    "text": "3.8",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "There is cwe data available from source Nvd, The value of the most recent CVSS (V3) score",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5969089"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://api.github.com/advisories/GHSA-xqmp-fxgv-xvq5"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34219"
                },
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34219.json"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/libp2p/rust-libp2p/security/advisories/GHSA-xqmp-fxgv-xvq5"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-gc42-3jg7-rxr2"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-xqmp-fxgv-xvq5"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34219"
                }
            ],
            "title": "CVE-2026-34219"
        }
    ]
}