vLLM: Denial of service via unvalidated multimodal processor kwargs

Summary

vLLM versions from 0.7.3 before 0.31.0 let remote clients set per-request multimodal processor parameters such as image size, patch count, crop count or frame count. For some processors (for example Isaac, InternVL and H2OVL), a single crafted request can exhaust memory and terminate the shared server process. The vendor advisory states that the API key is optional, so deployments without an external authentication layer can be reached without privileges. The impact is limited to availability; no confidentiality or integrity loss is claimed.

Affected

• vLLM from 0.7.3 before 0.31.0
• Relevant mainly for deployments that process multimodal (image or video) requests
• Unaffected: 0.31.0 and later (per vendor)

Fixed in

• Upgrade to vLLM 0.31.0 or later (fix merged in PR #58830)

Workaround

• Unknown. The vendor documents no workaround for affected versions other than upgrading.
• Put an authenticating reverse proxy in front of the API and restrict access to trusted clients (general mitigation, not from the vendor).

Exploitation

• No confirmed in-the-wild exploitation known.
• Not listed in CISA KEV according to a third-party aggregator; the CISA catalogue was not checked directly.
• CISA SSVC assessment: exploitation none, automatable yes, technical impact partial.
• No public proof of concept found.

Our recommendation

• Inventory all vLLM instances, versions, container images and bundled dependencies.
• Upgrade to vLLM 0.31.0 or later.
• Reject or restrict per-request multimodal processor settings for untrusted clients; move required settings to server configuration.
• Do not expose vLLM to the internet without authentication; monitor for repeated crashes or out-of-memory events.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• GitHub Security Advisory GHSA-gx7p-2j49-hfq4 (vendor) github.com
• VulnCheck advisory www.vulncheck.com
• OSV GHSA-gx7p-2j49-hfq4 osv.dev
• GitLab Advisory Database CVE-2026-114055 advisories.gitlab.com
• beri.net vLLM October 2026 advisories www.beri.net
• VulDB 423891 vuldb.com

Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 01:11.