Vulnerability-Lookup

CVE-2026-15957 (GCVE-0-2026-15957)

Vulnerability from cvelistv5 – Published: 2026-07-21 19:33 – Updated: 2026-07-22 18:25

Title

Uncontrolled recursion in smithy-rs generated JSON, CBOR, and XML deserializers allows unauthenticated remote denial of service via recursive shapes

Summary

Smithy-RS is a Rust code generation and runtime framework that generates HTTP clients and servers from Smithy interface definitions, powering the AWS SDK for Rust and custom service implementations. Uncontrolled recursion in the JSON, CBOR, and XML deserializer functions emitted by Amazon smithy-rs code generation could allow remote attackers to cause a denial of service (process abort via stack exhaustion) via a small request containing deeply nested data for a recursive model shape to a generated SDK or server. To mitigate this issue, users should upgrade to aws-sdk-rust release-2026-06-02 or later. Users building custom servers with smithy-rs codegen should regenerate from smithy-rs release-2026-06-01 or later.

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 (v2.0.3)

CWE

CWE-770 - Allocation of resources without limits or throttling

Assigner

AMZN

References

3 references

URL	Tags
https://github.com/awslabs/aws-sdk-rust/releases/…	release-notespatch
https://aws.amazon.com/security/security-bulletin…	vendor-advisory
https://github.com/smithy-lang/smithy-rs/security…	release-notes

Impacted products

1 product

Vendor	Product	Version
AWS	aws-sdk-rust	Affected: 0 , < release-2026-06-02 (custom)

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-15957

Vulnerability from fkie_nvd - Published: 2026-07-21 20:16 - Updated: 2026-07-22 20:37

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/2026-061-aws/
	ff89ba41-3aa1-4d27-914a-91399e9639e5	https://github.com/awslabs/aws-sdk-rust/releases/tag/release-2026-06-02
	ff89ba41-3aa1-4d27-914a-91399e9639e5	https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-4f2p-7j38-4xrg

Impacted products

	Vendor	Product	Version

JSON

To clipboard

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    }
  ],
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  "lastModified": "2026-07-22T20:37:38.603",
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          "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-2026-15957",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-22T18:15:34.870880Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-21T20:16:58.780",
  "references": [
    {
      "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
      "url": "https://aws.amazon.com/security/security-bulletins/2026-061-aws/"
    },
    {
      "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
      "url": "https://github.com/awslabs/aws-sdk-rust/releases/tag/release-2026-06-02"
    },
    {
      "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
      "url": "https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-4f2p-7j38-4xrg"
    }
  ],
  "sourceIdentifier": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ],
      "source": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
      "type": "Secondary"
    }
  ]
}

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.

Action not permitted

CVE-2026-15957 (GCVE-0-2026-15957)

FKIE_CVE-2026-15957

Tags

Sightings

Nomenclature