In the Linux kernel, the following vulnerability has been resolved: net: garp: fix unsigned integer underflow in garp_pdu_parse_attr The… (CVE-2026-63868)
A vulnerability in the Linux kernel's GARP attribute parser caused an unsigned integer underflow when computing the data length of received GARP attributes. This miscalculation leads to mismatched lengths during attribute processing, causing received Join/Leave events for common attributes like GVRP VLAN registration to be ignored and breaking the GARP receive path.
AI Analysis
Technical Summary
The Linux kernel's GARP attribute parser incorrectly computes the data length by subtracting the on-wire attribute length from the size of the attribute structure, resulting in an unsigned integer underflow. This underflow causes the length passed to garp_attr_lookup() to be truncated incorrectly, leading to ignored Join/Leave events for common GARP attributes. The vulnerability was fixed by correcting the data length calculation to subtract the header length from the attribute length.
Potential Impact
The vulnerability disrupts the proper processing of GARP Join/Leave events, which can break the GARP receive path for common attributes such as GVRP VLAN registration attributes. This may affect network functionality relying on GARP but does not indicate direct code execution or privilege escalation.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
In the Linux kernel, the following vulnerability has been resolved: net: garp: fix unsigned integer underflow in garp_pdu_parse_attr The… (CVE-2026-63868)
Description
A vulnerability in the Linux kernel's GARP attribute parser caused an unsigned integer underflow when computing the data length of received GARP attributes. This miscalculation leads to mismatched lengths during attribute processing, causing received Join/Leave events for common attributes like GVRP VLAN registration to be ignored and breaking the GARP receive path.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel's GARP attribute parser incorrectly computes the data length by subtracting the on-wire attribute length from the size of the attribute structure, resulting in an unsigned integer underflow. This underflow causes the length passed to garp_attr_lookup() to be truncated incorrectly, leading to ignored Join/Leave events for common GARP attributes. The vulnerability was fixed by correcting the data length calculation to subtract the header length from the attribute length.
Potential Impact
The vulnerability disrupts the proper processing of GARP Join/Leave events, which can break the GARP receive path for common attributes such as GVRP VLAN registration attributes. This may affect network functionality relying on GARP but does not indicate direct code execution or privilege escalation.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-3pm7-r452-gg96
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63868"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a5d27ac2a4a8d598913062f
Added to database: 07/19/2026, 19:38:20 UTC
Last enriched: 07/19/2026, 20:14:29 UTC
Last updated: 07/20/2026, 09:06:06 UTC
Views: 9
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