Answer in brief
CVE-2026-90110 records a Critical severity (CVSS 9.4) vulnerability in inetpeer: randomize RB-tree node comparison using SipHash. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 9.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=b145425f269a17ed344d737f746b844dfac60c82 <b20e98f0bb668a59abaf7bcf85d75c073e90d352 || >=b145425f269a17ed344d737f746b844dfac60c82 <5f127e3cc9647a8a70db12c65dbd0de473545380 || >=b145425f269a17ed344d737f746b844dfac60c82 <199fcf285e498111e029137d088949bc6c26d578 || >=b145425f269a17ed344d737f746b844dfac60c82 <857681f6835d5b0a7bc4a34a026baeaaf5215623 || >=b145425f269a17ed344d737f746b844dfac60c82 <7109bb63667a53e4542ad845476f97d0c8b28a61 || >=b145425f269a17ed344d737f746b844dfac60c82 <2ee66e9487172fcd189bc52a767c30dad7141c09 | b20e98f0bb668a59abaf7bcf85d75c073e90d352, 5f127e3cc9647a8a70db12c65dbd0de473545380, 199fcf285e498111e029137d088949bc6c26d578, 857681f6835d5b0a7bc4a34a026baeaaf5215623, 7109bb63667a53e4542ad845476f97d0c8b28a61, 2ee66e9487172fcd189bc52a767c30dad7141c09 |
| Linux/Linuxgeneric | 4.14 | Not reported |
Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 17, 2026
In the Linux kernel, the following vulnerability has been resolved: inetpeer: randomize RB-tree node comparison using SipHash The inetpeer rate limiting system stores peer entries in a Red-Black tree keyed deterministically on the remote IP address. Because tree lookups walk the RB-tree using standard lexicographical comparisons (inetpeer_addr_cmp), an off-path adversary can predict the exact topology of the tree and the sequence of nodes traversed during lookups (the gc_stack candidate list). By combining deterministic tree traversal with aggressive garbage collection (triggered when tree size exceeds inet_peer_threshold), an attacker can selectively force the eviction of targeted inet_peer nodes. When an evicted node is subsequently re-created upon receiving a new packet, its rate-limiting token bucket (rate_tokens, rate_last) is reset to full capacity. This creates a side-channel primitive allowing off-path attackers to bypass IP-keyed ICMP rate limits and infer open UDP ports (similar to SAD DNS style attacks). Mitigate this by randomizing the RB-tree node comparison logic using SipHash with a secret key (inetpeer_hash_key) initialized via net_get_random_once(). Nodes are ordered in the tree by SipHash(addr, key) rather than raw IP addresses. Because the secret key is unknown to external entities, the tree layout and lookup traversal paths are unpredictable to off-path adversaries, breaking the deterministic eviction gadget. Cache the computed 64-bit SipHash (hash) in struct inet_peer and compute the target hash (dhash) once at the beginning of inet_getpeer() to avoid recomputing SipHash at every step of the RB-tree walk.
Quoted source text, attributed separately from HOL analysis.