CVE-2026-90110: inetpeer: randomize RB-tree node comparison using SipHash
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.6%
EPSS score, percentile 49.2 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 9.4 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 4.14
Unaffected before 4.14; 6.1.188; 6.6.157; 6.12.110; 6.18.52; 7.2.6; and 1 more
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from b145425f269a to before b20e98f0bb66 |
| Affected | from b145425f269a to before 5f127e3cc964 |
| Affected | from b145425f269a to before 199fcf285e49 |
| Affected | from b145425f269a to before 857681f6835d |
| Affected | from b145425f269a to before 7109bb63667a |
| Affected | from b145425f269a to before 2ee66e948717 |
Versions not listed are: unaffected.
| Status | Versions |
|---|---|
| Affected | 4.14 |
| Unaffected | before 4.14 |
| Unaffected | 6.1.188 |
| Unaffected | 6.6.157 |
| Unaffected | 6.12.110 |
| Unaffected | 6.18.52 |
| Unaffected | 7.2.6 |
| Unaffected | 7.3 |
Versions not listed are: affected.
Versions the record lists as unaffected: 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6, 7.3.
Source: CVE List, as of . About the data.
About this vulnerability
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 t…
Summary: CVE record, as of .
- CISA has not added CVE-2026-90110 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 17 Sep 2026.
- The CVE record carries a CVSS v3.1 base score of 9.4 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.6% (percentile 49.2), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
inetpeer: randomize RB-tree node comparison using SipHash
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.
Source: CVE List, as of . About the data.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |
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