{"id":"CVE-2026-34219","aliases":["EUVD-2026-17521","GHSA-xqmp-fxgv-xvq5"],"status":"published","title":"libp2p-gossipsub: Gossipsub PRUNE Backoff Heartbeat Instant Overflow","description":"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.","severity":{"version":"4.0","score":8.2,"vector":"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00583,"percentile":0.48364,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-190","CWE-617"],"published":"2026-03-30T13:04:03Z","modified":"2026-07-24T20:10:00Z","fixes":[{"ecosystem":"crates.io","package":"libp2p-gossipsub","fixed_in":["0.49.4"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"libp2p-gossipsub","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.49.4"}]}]},{"source":"osv","ecosystem":"crates.io","package":"libp2p-gossipsub","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.49.4"}]}]}],"products":[{"vendor":"libp2p","product":"rust-libp2p"},{"vendor":"protocol","product":"libp2p-gossipsub"}],"references":[{"url":"https://github.com/libp2p/rust-libp2p/security/advisories/GHSA-xqmp-fxgv-xvq5","tags":["x_refsource_CONFIRM","Exploit","Vendor Advisory","web"]},{"url":"https://github.com/advisories/GHSA-gc42-3jg7-rxr2","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34219","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-xqmp-fxgv-xvq5"},{"url":"https://github.com/libp2p/rust-libp2p","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-34219","title":"libp2p-gossipsub: Gossipsub PRUNE Backoff Heartbeat Instant Overflow","description":"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.","status":"published","published":"2026-03-31T15:47:31.785Z","modified":"2026-03-31T17:34:57.667Z","cvss":[{"version":"4.0","score":8.2,"vector":"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","level":"high","assessor":"cna"}],"cwes":["CWE-190","CWE-617"],"updated_at":"2026-11-02T14:20:14.302133Z"}],"euvd":[{"id":"EUVD-2026-17521","description":"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.","status":"published","published":"2026-03-31T15:47:31Z","modified":"2026-03-31T17:34:57Z","cvss":[{"version":"4.0","score":8.2,"vector":"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","level":"high"}],"updated_at":"2026-11-02T19:25:24.891983Z"}],"ghsa":[{"id":"GHSA-xqmp-fxgv-xvq5","title":"libp2p-gossipsub: Remote crash via unchecked Instant overflow in heartbeat backoff expiry handling","description":"## 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.","status":"published","published":"2026-03-30T13:04:03Z","modified":"2026-04-06T23:13:24Z","cvss":[{"version":"4.0","score":8.2,"vector":"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","level":"high"},{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-190","CWE-617"],"updated_at":"2026-11-02T14:39:50.076383Z"}],"nvd":[{"id":"CVE-2026-34219","description":"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.","status":"published","published":"2026-03-31T16:16:31.92Z","modified":"2026-07-24T20:10:00.147Z","cvss":[{"version":"4.0","score":8.2,"vector":"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/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","level":"high","assessor":"secondary"},{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"}],"cwes":["CWE-190","CWE-617"],"updated_at":"2026-11-02T14:12:12.261218Z"}],"osv":[{"id":"GHSA-xqmp-fxgv-xvq5","title":"libp2p-gossipsub: Remote crash via unchecked Instant overflow in heartbeat backoff expiry handling","description":"## 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.","status":"published","published":"2026-03-30T13:04:03Z","modified":"2026-04-06T23:34:56.143916Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"medium"},{"version":"4.0","score":8.2,"vector":"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","level":"high"}],"cwes":["CWE-190","CWE-617"],"updated_at":"2026-11-02T15:47:00.198893Z"}]}}