What is the CVSS score of EUVD-2026-34101?

EUVD-2026-34101 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.0%.

Which versions of GoBGP are affected by EUVD-2026-34101?

GoBGP v4.3.0 contains a denial-of-service vulnerability in its BGP UPDATE message parser that allows unauthenticated attackers to crash or hang BGP speakers through integer underflow conditions.. A patch is available.

How to fix or mitigate EUVD-2026-34101?

Within 24 hours: Audit all GoBGP v4.3.0 deployments in production and classify by network criticality. Within 7 days: Evaluate upgrade pathways to newer GoBGP versions, assess compatibility impacts, and implement interim compensating controls for mission-critical BGP speakers. Within 30 days: Execute BGP speaker updates to patched versions once available or finalize long-term mitigation strategy if upgrades are not feasible.

GoBGP EUVD-2026-34101

| CVE-2026-37462 HIGH

Integer Overflow or Wraparound (CWE-190)

2026-06-03 mitre

GHSA-pw7p-7fqv-hpj8

Denial Of Service Integer Overflow Red Hat N A

7.5

CVSS 3.1 · Vendor: mitre

Severity by source

Vendor (mitre) PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SUSE

7.3 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Red Hat

7.5 HIGH

qualitative

Primary rating from Vendor (mitre).

CVSS VectorVendor: mitre

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Updated

Jun 04, 2026 - 14:28 vuln.today

v3 (cvss_changed)

Analysis Updated

Jun 04, 2026 - 14:28 vuln.today

v2 (cvss_changed)

Re-analysis Queued

Jun 04, 2026 - 14:22 vuln.today

cvss_changed

CVSS changed

Jun 04, 2026 - 14:22 NVD

7.3 (HIGH) 7.5 (HIGH)

Source Code Evidence Fetched

Jun 03, 2026 - 19:25 vuln.today

Analysis Generated

Jun 03, 2026 - 19:25 vuln.today

CVSS changed

Jun 03, 2026 - 19:22 NVD

7.3 (HIGH)

CVE Published

Jun 03, 2026 - 00:00 nvd

UNKNOWN (no severity yet)

DescriptionCVE.org

An integer underflow in the BGPUpdate.DecodeFromBytes function (/bgp/bgp.go) of gobgp v4.3.0 allows attackers to cause a Denial of Service (DoS) via supplying a crafted BGP UPDATE message.

AnalysisAI

Denial of service in GoBGP v4.3.0 allows unauthenticated remote attackers to crash or hang BGP speakers by sending a malformed BGP UPDATE message that triggers an integer underflow in the BGPUpdate.DecodeFromBytes parser. The underflow causes uint16 length counters (routelen and pathlen) to wrap to ~65k, leading the parser to silently consume the buffer or fail in ways that disrupt session processing. EPSS is very low (0.04%) and there is no public exploit identified at time of analysis, but the upstream commit demonstrating the bug is publicly visible.

Technical ContextAI

GoBGP is an open-source BGP (Border Gateway Protocol) implementation written in Go, widely used as a routing daemon and library in network automation, SDN, and route-server deployments. The flaw is a CWE-190 integer overflow/underflow in /pkg/packet/bgp/bgp.go: when decoding a BGP UPDATE, the parser subtracts the length of a withdrawn route or path attribute from a uint16 counter without first validating that the subtrahend does not exceed the remaining counter, so a crafted UPDATE whose announced WithdrawnRoutesLen or TotalPathAttributeLen is smaller than the actual encoded element causes the counter to wrap from a small value to ~65533/65535. The committed fix (9ce8936) adds explicit boundary checks that return a BGP MessageError before the subtraction occurs.

RemediationAI

Upstream fix available (commit 9ce8936672ebc07df524da77fa4c6ae26d92be6d on osrg/gobgp); a released patched version is not independently confirmed from the provided data, so operators should upgrade to the first tagged GoBGP release that includes this commit after v4.3.0, or apply the patch directly to vendored copies of pkg/packet/bgp/bgp.go. As compensating controls until upgrade, restrict BGP TCP/179 to known peer IPs at the host or perimeter firewall, enforce TCP-MD5 or TCP-AO authentication on all BGP sessions so only trusted neighbors can deliver UPDATE messages, and where supported deploy GTSM (RFC 5082) for eBGP sessions; these reduce exposure to malicious or spoofed peers but do not protect against a legitimate peer that is itself compromised. Operators should also monitor gobgpd for unexpected session resets and consider rate-limiting session re-establishment to limit DoS amplification.