Cisco IOS XR through 5.3.2 mishandles Local Packet Transport Services (LPTS) flow-base entries, which allows remote attackers to cause a denial of service (session drop) by making many connection attempts to open TCP ports, aka Bug ID CSCux95576.
Cisco IOS XR 4.2.0, 4.3.0, 5.0.0, 5.1.0, 5.2.0, 5.2.2, 5.2.4, 5.3.0, and 5.3.2 does not properly restrict the number of Path Computation Elements (PCEs) for OSPF LSA opaque area updates, which allows remote attackers to cause a denial of service (device reload) via a crafted update, aka Bug ID CSCuw83486.
Cisco IOS XR 4.3.4 through 5.3.0 on ASR 9000 devices, when uRPF, PBR, QoS, or an ACL is configured, does not properly handle bridge-group virtual interface (BVI) traffic, which allows remote attackers to cause a denial of service (chip and card hangs and reloads) by triggering use of a BVI interface for IPv4 packets, aka Bug ID CSCur62957.
The SNMPv2 implementation in Cisco IOS XR allows remote authenticated users to cause a denial of service (snmpd daemon reload) via a malformed SNMP packet, aka Bug ID CSCur25858.
Race condition in the lighttpd module in Cisco IOS XR 5.1 and earlier on Network Convergence System 6000 devices allows remote attackers to cause a denial of service (process reload) by establishing many TCP sessions, aka Bug ID CSCuq45239.
Cisco IOS XR on ASR 9000 devices does not properly use compression for port-range and address-range encoding, which allows remote attackers to bypass intended Typhoon line-card ACL restrictions via transit traffic, aka Bug ID CSCup30133.
Cisco IOS XR 5.1 and earlier on Network Convergence System 6000 devices allows remote attackers to cause a denial of service (NPU and card hang or reload) via a malformed MPLS packet, aka Bug ID CSCuq10466.