Vulnerability-Lookup

CVE-2026-18140 (GCVE-0-2026-18140)

Vulnerability from cvelistv5 – Published: 2026-07-30 18:34 – Updated: 2026-07-30 19:12

Title

Uncontrolled recursion in the aws-smithy-json unknown-key skip path allows unauthenticated remote denial of service in smithy-rs generated servers

Summary

Uncontrolled recursion in the unknown-key skip path of the aws-smithy-json runtime crate before 0.62.7, which the smithy-rs code generator invokes from every generated struct deserializer, might allow remote unauthenticated users to cause a denial of service (process abort via stack exhaustion) via a single small HTTP request containing deeply nested JSON to a smithy-rs generated server. To remediate this issue, users should upgrade to aws-smithy-json 0.62.7 or later and rebuild.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-30 19:12 UTC

CWE

CWE-674 - Uncontrolled Recursion

Assigner

AMZN mitre root

References

3 references

URL	Tags
https://crates.io/crates/aws-smithy-json/0.62.7	patch
https://aws.amazon.com/security/security-bulletin…	vendor-advisory
https://github.com/smithy-lang/smithy-rs/security…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version	CPE status
AWS	aws-smithy-json	Affected: 0.32.0 , ≤ 0.62.6 (custom) cpe:2.3:a:aws:aws-smithy-json::::::::

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-18140

Vulnerability from fkie_nvd - Published: 2026-07-30 19:17 - Updated: 2026-08-10 20:04

Severity

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

References

URL	Tags
ff89ba41-3aa1-4d27-914a-91399e9639e5	https://aws.amazon.com/security/security-bulletins/2026-067-aws/	Vendor Advisory
ff89ba41-3aa1-4d27-914a-91399e9639e5	https://crates.io/crates/aws-smithy-json/0.62.7	Product
ff89ba41-3aa1-4d27-914a-91399e9639e5	https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-8ffr-xgwf-xj56	Vendor Advisory

Impacted products

	Vendor	Product	Version
	amazon	aws-smithy-json	*

JSON

To clipboard

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    }
  ],
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  "lastModified": "2026-08-10T20:04:05.790",
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          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-18140",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-30T19:12:34.733029Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-30T19:17:26.457",
  "references": [
    {
      "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://aws.amazon.com/security/security-bulletins/2026-067-aws/"
    },
    {
      "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
      "tags": [
        "Product"
      ],
      "url": "https://crates.io/crates/aws-smithy-json/0.62.7"
    },
    {
      "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-8ffr-xgwf-xj56"
    }
  ],
  "sourceIdentifier": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-674"
        }
      ],
      "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
      "type": "Secondary"
    }
  ]
}

RHSA-2026:66521

Vulnerability from csaf_redhat - Published: 2026-09-10 16:42 - Updated: 2026-09-17 02:46

Summary

Red Hat Security Advisory: Logging for Red Hat OpenShift - 6.6.1

Severity

Important

Scope

23 vulnerabilities in this advisory, including CVE-2026-18140.

CVE-2026-18140

A flaw was found in aws-smithy-json. This vulnerability allows a remote, unauthenticated attacker to cause a denial of service (DoS) in smithy-rs generated servers. By sending a small HTTP request containing deeply nested JSON, the attacker can trigger uncontrolled recursion in the aws-smithy-json runtime, leading to stack exhaustion and a process abort. This can make the affected server unavailable to legitimate users.

7.5 (High)


                
                  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Fixed: 4 products Known not affected: 30 products

https://access.redhat.com/errata/RHSA-2026:66521

Open the full advisory

RHSA-2026:67593

Vulnerability from csaf_redhat - Published: 2026-09-15 18:06 - Updated: 2026-09-15 23:48

Summary

Red Hat Security Advisory: goose bug fix and enhancement update

Severity

Important

Scope

1 vulnerability in this advisory, including CVE-2026-18140.

CVE-2026-18140

7.5 (High)


                
                  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Fixed: 13 products

https://access.redhat.com/errata/RHSA-2026:67593

Open the full advisory

RHSA-2026:67595

Vulnerability from csaf_redhat - Published: 2026-09-15 18:06 - Updated: 2026-09-15 23:48

Summary

Red Hat Security Advisory: goose bug fix and enhancement update

Severity

Important

Scope

1 vulnerability in this advisory, including CVE-2026-18140.

CVE-2026-18140

7.5 (High)


                
                  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Fixed: 13 products

https://access.redhat.com/errata/RHSA-2026:67595

Open the full advisory

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-18140 (GCVE-0-2026-18140)

FKIE_CVE-2026-18140

RHSA-2026:66521

RHSA-2026:67593

RHSA-2026:67595

Tags

Sightings

Nomenclature

Related by attack behaviour