vLLM: ReDoS via structured_outputs.regex in the lm-format-enforcer backend (no compile timeout) — missed sibling of GHSA-rwxx-mrjm-wc2m

SummaryThe fix for GHSA-rwxx-mrjm-wc2m "ReDoS via structuredoutputs.regex compiled without timeout" wrapped the regex compile in the xgrammar and outlines backends with compileregexwithtimeout and, for outlines, validateregexisbuildable. The lm-format-enforcer backend was left unguarded: it...

PYSEC-2026-3933 vLLM: ReDoS via structured_outputs.regex in the lm-format-enforcer backend (no compile timeout) — missed sibling of GHSA-rwxx-mrjm-wc2m

Summary The fix for GHSA-rwxx-mrjm-wc2m "ReDoS via structuredoutputs.regex compiled without timeout" wrapped the regex compile in the xgrammar and outlines backends with compileregexwithtimeout and, for outlines, validateregexisbuildable. The lm-format-enforcer backend was left unguarded: it...

vLLM: ReDoS via structured_outputs.regex in the lm-format-enforcer backend (no compile timeout) — missed sibling of GHSA-rwxx-mrjm-wc2m

Summary The fix for GHSA-rwxx-mrjm-wc2m "ReDoS via structuredoutputs.regex compiled without timeout" wrapped the regex compile in the xgrammar and outlines backends with compileregexwithtimeout and, for outlines, validateregexisbuildable. The lm-format-enforcer backend was left unguarded: it...

GHSA-48JH-3GJ7-FG8V vLLM: ReDoS via structured_outputs.regex in the lm-format-enforcer backend (no compile timeout) — missed sibling of GHSA-rwxx-mrjm-wc2m

Summary The fix for GHSA-rwxx-mrjm-wc2m "ReDoS via structuredoutputs.regex compiled without timeout" wrapped the regex compile in the xgrammar and outlines backends with compileregexwithtimeout and, for outlines, validateregexisbuildable. The lm-format-enforcer backend was left unguarded: it...

CVE-2026-73556

A flaw was found in vLLM, an inference and serving engine for large language models. An unauthenticated remote attacker can exploit a Regular Expression Denial of Service ReDoS vulnerability in the lm-format-enforcer backend. By submitting a specially crafted regular expression through the...

Allocation of Resources Without Limits or Throttling

Overview vllm is an A high-throughput and memory-efficient inference and serving engine for LLMs Affected versions of this package are vulnerable to Allocation of Resources Without Limits or Throttling via the structuredoutputs.regex parameter in the lm-format-enforcer backend. An attacker can...

CVE-2026-73556

vLLM before 0.26.0 is affected by a DoS-like issue in the lm-format-enforcer backend: structured_outputs.regex is passed to RegexParser without compile_timeout or validation in validate_structured_output_request_lm_format_enforcer, allowing unauthenticated /v1/completions requests to consume CPU ...

CVE-2026-73556 vLLM: ReDoS via structured_outputs.regex in the lm-format-enforcer backend (no compile timeout) — missed sibling of CVE-2026-55574

vLLM is an inference and serving engine for large language models. Prior to 0.26.0, the structuredoutputs.regex parameter in vllm/v1/structuredoutput/backendlmformatenforcer.py is passed to lmformatenforcer.RegexParser without compileregexwithtimeout or validation in...

CVE-2026-73556 vLLM: ReDoS via structured_outputs.regex in the lm-format-enforcer backend (no compile timeout) — missed sibling of CVE-2026-55574

vLLM is an inference and serving engine for large language models. Prior to 0.26.0, the structuredoutputs.regex parameter in vllm/v1/structuredoutput/backendlmformatenforcer.py is passed to lmformatenforcer.RegexParser without compileregexwithtimeout or validation in...

CVE-2026-73556 vLLM: ReDoS via structured_outputs.regex in the lm-format-enforcer backend (no compile timeout) — missed sibling of CVE-2026-55574

vLLM is an inference and serving engine for large language models. Prior to 0.26.0, the structuredoutputs.regex parameter in vllm/v1/structuredoutput/backendlmformatenforcer.py is passed to lmformatenforcer.RegexParser without compileregexwithtimeout or validation in...

PT-2026-71671

Name of the Vulnerable Software and Affected Versions vLLM versions prior to 0.26.0 Description An unauthenticated request to the '/v1/completions' endpoint can cause a denial of service by consuming a CPU core and stalling the structured-output engine path. This occurs because the structured...