VulnerabilityPublished 16 Mar 2026

CVE-2026-30405: gobgp · CVE-2026-30405 is a high-severity

Affects gobgpSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Gogithub.com/osrg/gobgp`pkg:golang/github.com/osrg/gobgp`Other threats	Affected =4.2.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Immediately restrict BGP session access to trusted peers only, using network-level controls such as ACLs and firewall rules to block untrusted IP addresses from establishing BGP connections.
Implement prefix filtering and strict validation of BGP update messages to detect and reject malformed or suspicious NEXT_HOP attributes.
Monitor BGP daemon logs and network traffic for anomalies indicative of exploitation attempts, such as unexpected crashes or malformed BGP updates.
Deploy rate limiting on BGP update messages to reduce the risk of resource exhaustion attacks.
Isolate vulnerable GoBGP instances in segmented network zones to limit impact scope.
Engage with GoBGP maintainers and subscribe to security advisories for timely patch releases and apply updates promptly once available.
Consider deploying redundant BGP routers with failover capabilities to maintain routing availability during an attack.
Use BGP session authentication mechanisms (e.g., TCP MD5 signatures) to prevent unauthorized BGP session establishment where possible.
Conduct regular security assessments and penetration testing focused on BGP infrastructure to identify and remediate weaknesses proactively.

Description

CVE-2026-30405 is a high-severity vulnerability in GoBGP gobgpd version 4.2.0 that allows a remote attacker to cause a denial of service (DoS) by exploiting the NEXT_HOP path attribute. The vulnerability requires no authentication or user interaction and can be triggered remotely over the network. It impacts availability by crashing or disrupting the BGP daemon, potentially affecting network routing stability. No known exploits are currently in the wild, and no patches have been published yet. Organizations relying on GoBGP for BGP routing should prioritize monitoring and mitigation to prevent service disruption. The vulnerability is classified under CWE-400, indicating a resource exhaustion or DoS condition. Countries with significant internet infrastructure and use of GoBGP are at higher risk. Immediate mitigation involves network-level filtering and limiting exposure of BGP sessions to untrusted sources.

Impact

The primary impact of CVE-2026-30405 is on the availability of network routing services that rely on GoBGP gobgpd version 4.2.0. Successful exploitation can cause the BGP daemon to crash or become unresponsive, leading to denial of service conditions. This can disrupt routing tables and network traffic flow, potentially causing outages or degraded performance for internet service providers, data centers, cloud providers, and enterprises using GoBGP for BGP routing. The disruption could affect large-scale network infrastructure, impacting end-users and dependent services. Since BGP is foundational to internet routing, instability can propagate and cause broader network issues. The lack of authentication requirements and ease of exploitation increase the risk of attack from remote adversaries. However, the absence of known exploits in the wild and no reported integrity or confidentiality impacts somewhat reduce immediate risk severity. Organizations with exposed BGP sessions or those using vulnerable versions are at significant risk of service disruption.

Summary

CVE-2026-30405 is a vulnerability identified in GoBGP gobgpd version 4.2.0, a popular open-source BGP (Border Gateway Protocol) implementation used for routing decisions on the internet and private networks. The flaw resides in the handling of the NEXT_HOP path attribute, a critical component in BGP that specifies the next hop IP address for routing paths. An attacker can craft malicious BGP update messages containing specially manipulated NEXT_HOP attributes that cause the gobgpd daemon to enter a denial of service state, likely by triggering resource exhaustion or a crash (CWE-400). This vulnerability can be exploited remotely without requiring any authentication or user interaction, making it highly accessible to attackers who can reach the BGP session. The CVSS v3.1 base score is 7.5, reflecting a high severity due to its network attack vector, low attack complexity, no privileges required, and no user interaction needed. The impact is limited to availability, with no confidentiality or integrity compromise reported. No patches or fixes have been published at the time of disclosure, and no active exploitation has been observed. Given the critical role of BGP in internet routing, exploitation could disrupt network traffic flow, causing outages or degraded service for affected networks.

CWE-400Uncontrolled Resource Consumption (opens in a new tab)
Class weaknessLikelihood of exploit: High
The product does not properly control the allocation and maintenance of a limited resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place.
Architecture and Design
Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or; uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Regular Expression Exponential Blowup (opens in a new tab)
Sustained Client Engagement (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/osrg/gobgp/issues/3305 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Mar 2026, 01:01 UTC

WeaknessesCWE-400

Technical details

References

Community reviews

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