CVE-2026-105755
Description
A flaw was found in vLLM. When handling flash late-interaction scoring and reranking requests, internal cache keys are derived directly from user-supplied request identifiers. A remote attacker can exploit this issue by submitting concurrent requests reusing a victim's request identifier to overwrite cached query data. Consequently, this flaw allows attackers to corrupt the scoring results returned to legitimate users or cause a denial of service (DoS) through transient cache errors.
Statement
A moderate severity flaw was found in vLLM, the inference and serving engine used by Red Hat AI Inference Server and Red Hat OpenShift AI (RHOAI). When handling flash late-interaction scoring and reranking requests at the /score and /rerank endpoints, vLLM caches each request's query embedding under a key derived from the caller-controlled X-Request-Id header. A remote attacker with API client access who obtains or predicts a victim's request identifier and submits a precisely timed concurrent request reusing it can overwrite the victim's cached query embedding, so the victim's documents are scored against the attacker's query and the scoring results returned to the victim are corrupted. Collisions on shared use counters can also trigger transient late-interaction cache-miss errors, causing denial of service for individual requests. The flaw does not disclose confidential information to the attacker. Red Hat and upstream both rate this issue moderate severity with a CVSS 3.1 score of 4.2 (AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L). Red Hat has deferred a fix for the affected Red Hat AI Inference Server and Red Hat OpenShift AI releases because the impact is moderate and the CVSS score is below 7.0; the residual risk is limited to corruption of individual scoring or reranking responses and transient request failures.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.2 | N/A | 4.2 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L
cve.org: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L
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