XGrammar affected by Denial of Service by infinite recursion grammars
mlc-ai · xgrammar
7.7HighCVSS 4.0
Recommended action
Within 7 days
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Patch available
Direct vendor intelligence
Authoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
1 current
CVE-2025-57809 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityxgrammar: XGrammar affected by Denial of Service by infinite recursion grammars
2 known affected
The vendor explicitly identifies these products as affected by this CVE.
rhaiis/vllm-cuda-rhel9 as a component of Red Hat AI Inference Server
rhaiis/vllm-rocm-rhel9 as a component of Red Hat AI Inference Server
Summary
A flaw was found in xgrammar. Recursive grammar definitions could trigger infinite recursion during parsing in GrammarMatcherBase::ExpandEquivalentStackElements, leading to unbounded stack growth and a segmentation fault. This vulnerability allows remote attackers to cause a denial of service (DoS) when untrusted grammar is processed.
Remediation
For more information visit https://access.redhat.com/errata/RHSA-2025:19427
Optional official sources
National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.
Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.
Official European source
ENISA European Vulnerability Database
Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.
1 current
ENISA EUVD identifier
EUVD-2025-28633
No EUVD known-exploited evidence
ENISA has published the identifier mapping but no EUVD description has been stored yet.
EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Patch available
01
What, why and how
XGrammar is an open-source library for efficient, flexible, and portable structured generation. Prior to version 0.1.21, XGrammar has an infinite recursion issue in the grammar. This issue has been resolved in version 0.1.21.
What
XGrammar is an open-source library for efficient, flexible, and portable structured generation. Prior to version 0.1.21, XGrammar has an infinite recursion issue in the grammar. This issue has been resolved in version 0.1.21.
Why
The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
XGrammar is an open-source library for efficient, flexible, and portable structured generation. Prior to version 0.1.21, XGrammar has an infinite recursion issue in the grammar. This issue has been resolved in version 0.1.21.
Why
The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No confirmed evidence
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.Reference recorded
A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.
Likely attack path
a network path → Uncontrolled Recursion → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness ?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-674: Uncontrolled Recursion. The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
CVSS vector ?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VINoneVulnerable-system integrity: No direct loss is represented by this metric.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
Operational remediation based on structured source evidence.
Status ?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
rhaiis/vllm-cuda-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-rocm-rhel9 as a component of Red Hat AI Inference Server
Fixed
registry.redhat.io/rhelai1/bootc-amd-rhel9@sha256:c029b66a3354ee6fd186a1f05aff31b5834e611b9d5b326b65b16829d6b98d1f_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-aws-nvidia-rhel9@sha256:385028a96717418982de197f8f0a9052edf12f80a50bd8ab53ca72203a4ba5d8_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-azure-amd-rhel9@sha256:f77167ea53b46b91631679ed84aab2373ff56dc62cba946296be212443bc2a99_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-azure-nvidia-rhel9@sha256:427596ae2591a30a0218b7cfdd858ccad96178ddc2618cdf0a6e4e9af36685bf_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-gcp-nvidia-rhel9@sha256:a83229f005c78e271c774f3eda26421fedbc4b8cf1ac3fe94234899c6d677124_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-intel-rhel9@sha256:601064840ac29ea7d4a977efb506df226a2931d5079ec9f432bdf60095bf7c2e_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-nvidia-rhel9@sha256:0efbdee5f2ec93477b5aac5dd4c1dd9b31fe96e5e7c7dd701738ceaa86b2f2eb_arm64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-nvidia-rhel9@sha256:dd412fc0dde3dee492839c28f8ed003bb17fe5fe1be375031b24c84bb36fb8cd_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-amd-rhel9@sha256:03f22e965af16fe84aed7d30e7b8db00dead11d9fd4b11e3c9abb2e68dd910f1_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-intel-rhel9@sha256:cf0ec4ad1520ff2ce83420846830286e036f310f880cf8a533f0966c35ebd32f_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-nvidia-rhel9@sha256:a17f53b6c19150fce3e6d456fde71a74bdab5da5eeb44bec7791084c3471a98e_arm64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-nvidia-rhel9@sha256:a7e2df4276aaba0d23430c7c3314e05b005fe5628d588bc1f4f979a35571fa5c_amd64 as a component of Red Hat Enterprise Linux AI 1.5
Action
For more information visit https://access.redhat.com/errata/RHSA-2025:19427
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 25 Aug 2025 · Last source change 26 Aug 2025, 20:19 UTC · CWE-674 · Uncontrolled Recursion
CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source ?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2025-28633
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Affected versionsThe structured affected or fixed version information changed.
Before
rhaiis/vllm-cuda-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-rocm-rhel9 as a component of Red Hat AI Inference Server · Fixed: registry.redhat.io/rhelai1/bootc-amd-rhel9@sha256:c029b66a3354ee6fd186a1f05aff31b5834e611b9d5b326b65b16829d6b98d1f_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-aws-nvidia-rhel9@sha256:385028a96717418982de197f8f0a9052edf12f80a50bd8ab53ca72203a4ba5d8_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-azure-amd-rhel9@sha256:f77167ea53b46b91631679ed84aab2373ff56dc62cba946296be212443bc2a99_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-azure-nvidia-rhel9@sha256:427596ae2591a30a0218b7cfdd858ccad96178ddc2618cdf0a6e4e9af36685bf_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-gcp-nvidia-rhel9@sha256:a83229f005c78e271c774f3eda26421fedbc4b8cf1ac3fe94234899c6d677124_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-intel-rhel9@sha256:601064840ac29ea7d4a977efb506df226a2931d5079ec9f432bdf60095bf7c2e_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-nvidia-rhel9@sha256:0efbdee5f2ec93477b5aac5dd4c1dd9b31fe96e5e7c7dd701738ceaa86b2f2eb_arm64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-nvidia-rhel9@sha256:dd412fc0dde3dee492839c28f8ed003bb17fe5fe1be375031b24c84bb36fb8cd_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/instructlab-amd-rhel9@sha256:03f22e965af16fe84aed7d30e7b8db00dead11d9fd4b11e3c9abb2e68dd910f1_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/instructlab-intel-rhel9@sha256:cf0ec4ad1520ff2ce83420846830286e036f310f880cf8a533f0966c35ebd32f_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/instructlab-nvidia-rhel9@sha256:a17f53b6c19150fce3e6d456fde71a74bdab5da5eeb44bec7791084c3471a98e_arm64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/instructlab-nvidia-rhel9@sha256:a7e2df4276aaba0d23430c7c3314e05b005fe5628d588bc1f4f979a35571fa5c_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2
After
rhaiis/vllm-cuda-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-rocm-rhel9 as a component of Red Hat AI Inference Server · Fixed: registry.redhat.io/rhelai1/bootc-amd-rhel9@sha256:c029b66a3354ee6fd186a1f05aff31b5834e611b9d5b326b65b16829d6b98d1f_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-aws-nvidia-rhel9@sha256:385028a96717418982de197f8f0a9052edf12f80a50bd8ab53ca72203a4ba5d8_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-azure-amd-rhel9@sha256:f77167ea53b46b91631679ed84aab2373ff56dc62cba946296be212443bc2a99_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-azure-nvidia-rhel9@sha256:427596ae2591a30a0218b7cfdd858ccad96178ddc2618cdf0a6e4e9af36685bf_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-gcp-nvidia-rhel9@sha256:a83229f005c78e271c774f3eda26421fedbc4b8cf1ac3fe94234899c6d677124_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-intel-rhel9@sha256:601064840ac29ea7d4a977efb506df226a2931d5079ec9f432bdf60095bf7c2e_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-nvidia-rhel9@sha256:0efbdee5f2ec93477b5aac5dd4c1dd9b31fe96e5e7c7dd701738ceaa86b2f2eb_arm64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-nvidia-rhel9@sha256:dd412fc0dde3dee492839c28f8ed003bb17fe5fe1be375031b24c84bb36fb8cd_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-amd-rhel9@sha256:03f22e965af16fe84aed7d30e7b8db00dead11d9fd4b11e3c9abb2e68dd910f1_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-intel-rhel9@sha256:cf0ec4ad1520ff2ce83420846830286e036f310f880cf8a533f0966c35ebd32f_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-nvidia-rhel9@sha256:a17f53b6c19150fce3e6d456fde71a74bdab5da5eeb44bec7791084c3471a98e_arm64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-nvidia-rhel9@sha256:a7e2df4276aaba0d23430c7c3314e05b005fe5628d588bc1f4f979a35571fa5c_amd64 as a component of Red Hat Enterprise Linux AI 1.5
Affected versionsThe structured affected or fixed version information changed.
Before
rhaiis/vllm-cuda-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-rocm-rhel9 as a component of Red Hat AI Inference Server · Fixed: registry.redhat.io/rhelai1/bootc-amd-rhel9@sha256:c029b66a3354ee6fd186a1f05aff31b5834e611b9d5b326b65b16829d6b98d1f_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-aws-nvidia-rhel9@sha256:385028a96717418982de197f8f0a9052edf12f80a50bd8ab53ca72203a4ba5d8_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-azure-amd-rhel9@sha256:f77167ea53b46b91631679ed84aab2373ff56dc62cba946296be212443bc2a99_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-azure-nvidia-rhel9@sha256:427596ae2591a30a0218b7cfdd858ccad96178ddc2618cdf0a6e4e9af36685bf_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-gcp-nvidia-rhel9@sha256:a83229f005c78e271c774f3eda26421fedbc4b8cf1ac3fe94234899c6d677124_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-intel-rhel9@sha256:601064840ac29ea7d4a977efb506df226a2931d5079ec9f432bdf60095bf7c2e_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-nvidia-rhel9@sha256:0efbdee5f2ec93477b5aac5dd4c1dd9b31fe96e5e7c7dd701738ceaa86b2f2eb_arm64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/bootc-nvidia-rhel9@sha256:dd412fc0dde3dee492839c28f8ed003bb17fe5fe1be375031b24c84bb36fb8cd_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-amd-rhel9@sha256:03f22e965af16fe84aed7d30e7b8db00dead11d9fd4b11e3c9abb2e68dd910f1_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-intel-rhel9@sha256:cf0ec4ad1520ff2ce83420846830286e036f310f880cf8a533f0966c35ebd32f_amd64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-nvidia-rhel9@sha256:a17f53b6c19150fce3e6d456fde71a74bdab5da5eeb44bec7791084c3471a98e_arm64 as a component of Red Hat Enterprise Linux AI 1.5; registry.redhat.io/rhelai1/instructlab-nvidia-rhel9@sha256:a7e2df4276aaba0d23430c7c3314e05b005fe5628d588bc1f4f979a35571fa5c_amd64 as a component of Red Hat Enterprise Linux AI 1.5
After
rhaiis/vllm-cuda-rhel9 as a component of Red Hat AI Inference Server; rhaiis/vllm-rocm-rhel9 as a component of Red Hat AI Inference Server · Fixed: registry.redhat.io/rhelai1/bootc-amd-rhel9@sha256:c029b66a3354ee6fd186a1f05aff31b5834e611b9d5b326b65b16829d6b98d1f_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-aws-nvidia-rhel9@sha256:385028a96717418982de197f8f0a9052edf12f80a50bd8ab53ca72203a4ba5d8_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-azure-amd-rhel9@sha256:f77167ea53b46b91631679ed84aab2373ff56dc62cba946296be212443bc2a99_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-azure-nvidia-rhel9@sha256:427596ae2591a30a0218b7cfdd858ccad96178ddc2618cdf0a6e4e9af36685bf_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-gcp-nvidia-rhel9@sha256:a83229f005c78e271c774f3eda26421fedbc4b8cf1ac3fe94234899c6d677124_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-intel-rhel9@sha256:601064840ac29ea7d4a977efb506df226a2931d5079ec9f432bdf60095bf7c2e_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-nvidia-rhel9@sha256:0efbdee5f2ec93477b5aac5dd4c1dd9b31fe96e5e7c7dd701738ceaa86b2f2eb_arm64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/bootc-nvidia-rhel9@sha256:dd412fc0dde3dee492839c28f8ed003bb17fe5fe1be375031b24c84bb36fb8cd_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/instructlab-amd-rhel9@sha256:03f22e965af16fe84aed7d30e7b8db00dead11d9fd4b11e3c9abb2e68dd910f1_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/instructlab-intel-rhel9@sha256:cf0ec4ad1520ff2ce83420846830286e036f310f880cf8a533f0966c35ebd32f_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/instructlab-nvidia-rhel9@sha256:a17f53b6c19150fce3e6d456fde71a74bdab5da5eeb44bec7791084c3471a98e_arm64 as a component of Red Hat Enterprise Linux AI 1.5.2; registry.redhat.io/rhelai1/instructlab-nvidia-rhel9@sha256:a7e2df4276aaba0d23430c7c3314e05b005fe5628d588bc1f4f979a35571fa5c_amd64 as a component of Red Hat Enterprise Linux AI 1.5.2
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
CVE-2025-57809: XGrammar affected by Denial of Service by infinite recursion grammars | BlackTree
