VYPR
High severity7.3NVD Advisory· Published May 4, 2026· Updated May 6, 2026

CVE-2026-7736

CVE-2026-7736

Description

A vulnerability was determined in osrg GoBGP up to 4.3.0. Affected by this vulnerability is the function parseRibEntry of the file pkg/packet/mrt/mrt.go. Executing a manipulation can lead to integer underflow. It is possible to launch the attack remotely. Upgrading to version 4.4.0 addresses this issue. This patch is called 76d911046344a3923cbe573364197aa081944592. It is suggested to upgrade the affected component.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
github.com/osrg/gobgp/v4Go
< 4.4.04.4.0

Affected products

2
  • Osrg/Gobgpinferred2 versions
    <=4.3.0+ 1 more
    • (no CPE)range: <=4.3.0
    • cpe:2.3:a:osrg:gobgp:*:*:*:*:*:*:*:*range: <4.4.0

Patches

1
76d911046344

packet/mrt: fix uint16 underflow in parseRibEntry path attribute loop

https://github.com/osrg/gobgpFUJITA TomonoriApr 1, 2026via ghsa
1 file changed · +7 3
  • pkg/packet/mrt/mrt.go+7 3 modified
    @@ -413,6 +413,9 @@ func parseRibEntry(data []byte, family bgp.Family, isAddPath bool, prefix ...bgp
     	}
     	totalLen := binary.BigEndian.Uint16(data[:2])
     	data = data[2:]
    +	if len(data) < int(totalLen) {
    +		return nil, nil, errNotAllRibEntryBytesAvailable
    +	}
     	options := &bgp.MarshallingOption{
     		MRT: true,
     	}
    @@ -441,10 +444,11 @@ func parseRibEntry(data []byte, family bgp.Family, isAddPath bool, prefix ...bgp
     			mp.Value = []bgp.PathNLRI{{NLRI: prefix[0], ID: e.PathIdentifier}}
     		}
     
    -		attrLen -= uint16(p.Len())
    -		if len(data) < p.Len() {
    -			return nil, nil, errNotAllRibEntryBytesAvailable
    +		pLen := uint16(p.Len())
    +		if pLen > attrLen {
    +			return nil, nil, fmt.Errorf("path attribute length %d exceeds remaining attribute length %d", pLen, attrLen)
     		}
    +		attrLen -= pLen
     		data = data[p.Len():]
     		e.PathAttributes = append(e.PathAttributes, p)
     	}
    

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

7

News mentions

0

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