CVE-2026-74281 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
tipc: reject inverted service ranges from peer bindings
tipc_update_nametbl() inserts a binding advertised by a peer node using the lower and upper service-range bounds taken directly from the wire, without checking that lower <= upper. The local bind path validates the ordering (tipc_uaddr_valid()), but the name-distribution path does not.
A binding with lower > upper is inserted at the far end of the service-range rbtree (keyed on lower) where no lookup or withdrawal can ever match it (service_range_foreach_match() requires sr->lower <= end). The publication, its service_range node and the augmented rbtree entry are then leaked for the lifetime of the namespace, and there is no per-peer cap equivalent to TIPC_MAX_PUBL on locally created bindings.
Reject inverted ranges in the network path as well. A peer node can otherwise leak unbounded binding-table memory by sending PUBLICATION items with lower > upper.
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Analysis
by VulDB Data Team • 08/15/2026
The vulnerability described affects the Linux kernel's TIPC (Transparent Inter-Process Communication) implementation, specifically within the name table management functionality. This issue represents a memory exhaustion vulnerability that stems from inadequate input validation in the network path of service range handling. The flaw exists in the tipc_update_nametbl() function which processes binding advertisements from peer nodes without performing proper validation of the service range bounds before insertion into the local data structures.
The technical root cause lies in the asymmetric validation approach within TIPC's implementation where the local bind path properly validates ordering through tipc_uaddr_valid() function but the name-distribution path lacks this crucial check. When a peer node sends a PUBLICATION message containing service range bounds where the lower bound exceeds the upper bound, this malformed data is accepted and inserted into the service-range red-black tree structure. The tree is keyed on the lower bound value, causing inverted ranges to be positioned at the far end of the tree structure where they become unreachable through normal lookup operations.
The operational impact of this vulnerability manifests as memory leakage within the TIPC namespace, with binding table entries and associated service_range nodes remaining allocated indefinitely. This represents a classic resource exhaustion attack vector that can lead to system instability and denial of service conditions. The lack of per-peer caps equivalent to TIPC_MAX_PUBL on locally created bindings exacerbates the issue by allowing unlimited memory consumption from a single malicious peer node. Service_range_foreach_match() function enforces sr->lower <= end constraint during lookups, making it impossible to match or remove these inverted range entries once they are inserted.
This vulnerability aligns with CWE-129 and CWE-704 categories related to improper input validation and memory management issues. The attack pattern follows ATT&CK technique T1499.004 for resource exhaustion through malformed data processing. The flaw demonstrates poor defensive programming practices where input validation is applied inconsistently across different code paths within the same subsystem, creating exploitable gaps in security controls. The memory leak occurs because inverted ranges cannot be matched or removed during normal operation, creating persistent allocation overhead that accumulates over time.
The mitigation strategy involves implementing identical validation checks in both the local bind path and the name-distribution path to ensure that service range bounds are properly ordered before insertion into the data structures. This requires modifying tipc_update_nametbl() to validate lower <= upper constraints on peer-provided service ranges similar to how local bindings are validated. Additionally, implementing per-peer limits comparable to TIPC_MAX_PUBL would prevent any single peer from consuming excessive resources through repeated malicious publications. The fix should also include proper error handling for malformed range data to ensure that invalid entries are rejected rather than silently inserted into the system.