CVE-2026-7736
Integer Underflow in GoBGP
Publication date: 2026-05-04
Last updated on: 2026-05-06
Assigner: VulDB
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| osrg | gobgp | to 4.4.0 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-189 | |
| CWE-191 | The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the osrg GoBGP software up to version 4.3.0, specifically in the parseRibEntry function of the file pkg/packet/mrt/mrt.go. It involves an integer underflow caused by missing bounds checks in the path attribute loop, which can be triggered by manipulating input data. This flaw allows an attacker to cause unexpected behavior during the parsing of BGP routing information.
The vulnerability can be exploited remotely, meaning an attacker does not need local access to launch the attack. The issue was fixed in version 4.4.0 by adding proper validation checks to prevent the underflow and ensure malformed input is handled safely.
How can this vulnerability impact me? :
Exploiting this vulnerability can lead to integer underflow during the processing of BGP routing information, which may cause the GoBGP software to behave incorrectly or crash. This can disrupt network routing operations, potentially leading to denial of service or instability in network communications.
Since the attack can be launched remotely without authentication, it poses a significant risk to network infrastructure relying on vulnerable versions of GoBGP.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability affects the parseRibEntry function in GoBGP versions up to 4.3.0 and involves an integer underflow triggered by malformed MRT packets. Detection would involve monitoring GoBGP logs for errors related to MRT packet parsing or unexpected crashes.
Since the vulnerability is in GoBGP's MRT packet parsing, you can check the GoBGP version running on your system to identify if it is vulnerable.
- Check GoBGP version: `gobgp version`
- Monitor GoBGP logs for errors related to MRT parsing or crashes.
- Use network packet capture tools (e.g., tcpdump or Wireshark) to inspect BGP MRT packets for malformed attributes that could trigger the vulnerability.
What immediate steps should I take to mitigate this vulnerability?
The primary mitigation step is to upgrade GoBGP to version 4.4.0 or later, which includes the patch that fixes the integer underflow vulnerability in the parseRibEntry function.
Until the upgrade can be applied, consider monitoring and filtering suspicious MRT packets that could exploit the vulnerability, although no specific workaround commands are provided.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not include any details on how this vulnerability impacts compliance with common standards or regulations such as GDPR or HIPAA.