{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-73556", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-08-12T20:53:46.380Z", "datePublished": "2026-08-13T14:56:52.569Z", "dateUpdated": "2026-08-13T14:56:52.569Z"}, "containers": {"cna": {"title": "vLLM: ReDoS via structured_outputs.regex in the lm-format-enforcer backend (no compile timeout) \u2014 missed sibling of CVE-2026-55574", "problemTypes": [{"descriptions": [{"cweId": "CWE-400", "lang": "en", "description": "CWE-400: Uncontrolled Resource Consumption", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-1333", "lang": "en", "description": "CWE-1333: Inefficient Regular Expression Complexity", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}}], "references": [{"name": "https://github.com/vllm-project/vllm/security/advisories/GHSA-48jh-3gj7-fg8v", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/vllm-project/vllm/security/advisories/GHSA-48jh-3gj7-fg8v"}, {"name": "https://github.com/vllm-project/vllm/pull/47595", "tags": ["x_refsource_MISC"], "url": "https://github.com/vllm-project/vllm/pull/47595"}, {"name": "https://github.com/vllm-project/vllm/commit/c9a788eedc412acceaa5112e0d44624b49841577", "tags": ["x_refsource_MISC"], "url": "https://github.com/vllm-project/vllm/commit/c9a788eedc412acceaa5112e0d44624b49841577"}, {"name": "https://github.com/vllm-project/vllm/releases/tag/v0.26.0", "tags": ["x_refsource_MISC"], "url": "https://github.com/vllm-project/vllm/releases/tag/v0.26.0"}], "affected": [{"vendor": "vllm-project", "product": "vllm", "versions": [{"version": "< 0.26.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-13T14:56:52.569Z"}, "descriptions": [{"lang": "en", "value": "vLLM is an inference and serving engine for large language models. Prior to 0.26.0, the structured_outputs.regex parameter in vllm/v1/structured_output/backend_lm_format_enforcer.py is passed to lmformatenforcer.RegexParser without compile_regex_with_timeout or validation in validate_structured_output_request_lm_format_enforcer, allowing an unauthenticated /v1/completions request against the lm-format-enforcer backend to consume a CPU core and stall the structured-output engine path with a catastrophic regular expression. This issue is fixed in version 0.26.0."}], "source": {"advisory": "GHSA-48jh-3gj7-fg8v", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "vllm", "vendor": "vllm-project", "versions": [{"status": "affected", "version": "< 0.26.0"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "vLLM is an inference and serving engine for large language models. Prior to 0.26.0, the structured_outputs.regex parameter in vllm/v1/structured_output/backend_lm_format_enforcer.py is passed to lmformatenforcer.RegexParser without compile_regex_with_timeout or validation in validate_structured_output_request_lm_format_enforcer, allowing an unauthenticated /v1/completions request against the lm-format-enforcer backend to consume a CPU core and stall the structured-output engine path with a catastrophic regular expression. This issue is fixed in version 0.26.0."}], "id": "CVE-2026-73556", "lastModified": "2026-08-13T15:20:17.927", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-08-13T15:20:17.927", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/vllm-project/vllm/commit/c9a788eedc412acceaa5112e0d44624b49841577"}, {"source": "security-advisories@github.com", "url": "https://github.com/vllm-project/vllm/pull/47595"}, {"source": "security-advisories@github.com", "url": "https://github.com/vllm-project/vllm/releases/tag/v0.26.0"}, {"source": "security-advisories@github.com", "url": "https://github.com/vllm-project/vllm/security/advisories/GHSA-48jh-3gj7-fg8v"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}, {"lang": "en", "value": "CWE-1333"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}