CVE-2026-7736Network attack vector

MRT parsing disruption via attribute-length underflow

Published May 4, 2026 · Updated May 4, 2026

Integer underflow in GoBGP 4.0 through 4.3.0 allows remote attackers to disrupt MRT RIB parsing through malformed attributes. The parseRibEntry loop subtracts each decoded path attribute length from a uint16 remaining-length counter before checking whether the attribute exceeds that counter. Reachability requires untrusted MRT-encoded RIB data to enter the parser; published materials do not identify a specific crash or broader routing consequence.

CVSS severity7.5
High
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in GoBGP 4.0 through 4.3.0 allows remote attackers to disrupt MRT RIB parsing through malformed attributes. The parseRibEntry loop subtracts each decoded path attribute length from a uint16 remaining-length counter before checking whether the attribute exceeds that counter. Reachability requires untrusted MRT-encoded RIB data to enter the parser; published materials do not identify a specific crash or broader routing consequence.

The record

CVE
CVE-2026-7736
Published
May 4, 2026
Updated
May 4, 2026
Vendor
GoBGP
Product
GoBGP
Classifications
CWE-189, CWE-191, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 4, 2026CVE publishedPublication date reported by the CVE source.
  2. May 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.0
  2. Affected versionversion=4.1
  3. Affected versionversion=4.2
  4. Affected versionversion=4.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GoBGP · GoBGPversion=4.0; version=4.1; version=4.2; version=4.3.0

Published CVSS scores

7.5VulDBAV:N/AC:L/Au:N/C:P/I:P/A:P
6.9VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
7.3VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-189Numeric Errors
CWE-191Integer Underflow (Wrap or Wraparound)
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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