Vulnerability-Lookup

GHSA-4V6F-7VJH-6X4M

Vulnerability from github – Published: 2026-10-23 20:48 – Updated: 2026-10-23 20:48

Summary

Strands Agents SDK: Exposure of data element to wrong session in the A2A Server

Details

Summary
Strands Agents SDK is an open-source SDK, available for Python (strands-agents) and TypeScript (@strands-agents/sdk), for building and running AI agents. An issue exists where, under certain circumstances, the Agent2Agent (A2A) server shares conversation history across callers with different context_id values, allowing one caller to read and influence another caller's session.

Impact
The A2A server did not properly isolate conversation state between callers. In multi-tenant deployments, an authenticated remote user could access another caller's conversation history or influence model behavior for other callers (CWE-488: Unintended Disclosure of Data Element to Wrong Session). This affects any deployment where an A2A server is reachable by more than one user or tenant.

Impacted versions:
strands-agents (Python): all versions containing the multiagent.a2a module, < 1.43.0
@strands-agents/sdk (TypeScript): < 1.5.0

Patches
This issue has been addressed in strands-agents version 1.43.0 and @strands-agents/sdk version 1.5.0. The A2A server now uses an agent factory so conversation state is isolated per A2A context_id. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.

Workarounds
There is no workaround that fully addresses this issue in affected versions. Until you upgrade, do not expose an A2A server to more than one user or tenant. If multiple callers need access, run a separate A2A server instance for each user or tenant.

References
If you have any questions or comments about this advisory, we ask that you contact AWS Security via our vulnerability reporting page or directly via email to aws-security@amazon.com. Please do not create a public GitHub issue.

Severity

8.1 (High)


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

8.6 (High)


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

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "strands-agents"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.43.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@strands-agents/sdk"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.5.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-115419"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-488"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-23T20:48:29Z",
    "nvd_published_at": "2026-10-22T21:17:17Z",
    "severity": "HIGH"
  },
  "details": "**Summary**  \nStrands Agents SDK is an open-source SDK, available for Python (strands-agents) and TypeScript (@strands-agents/sdk), for building and running AI agents. An issue exists where, under certain circumstances, the Agent2Agent (A2A) server shares conversation history across callers with different context\\_id values, allowing one caller to read and influence another caller\u0027s session.  \n  \n**Impact**  \nThe A2A server did not properly isolate conversation state between callers. In multi-tenant deployments, an authenticated remote user could access another caller\u0027s conversation history or influence model behavior for other callers (CWE-488: Unintended Disclosure of Data Element to Wrong Session). This affects any deployment where an A2A server is reachable by more than one user or tenant.  \n  \n**Impacted versions:**  \nstrands-agents (Python): all versions containing the multiagent.a2a module, \u003c 1.43.0  \n@strands-agents/sdk (TypeScript): \u003c 1.5.0  \n  \n**Patches**  \nThis issue has been addressed in strands-agents version 1.43.0 and @strands-agents/sdk version 1.5.0. The A2A server now uses an agent factory so conversation state is isolated per A2A context\\_id. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.  \n  \n**Workarounds**  \nThere is no workaround that fully addresses this issue in affected versions. Until you upgrade, do not expose an A2A server to more than one user or tenant. If multiple callers need access, run a separate A2A server instance for each user or tenant.  \n  \n**References**  \nIf you have any questions or comments about this advisory, we ask that you contact AWS Security via our [vulnerability reporting page](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). Please do not create a public GitHub issue.",
  "id": "GHSA-4v6f-7vjh-6x4m",
  "modified": "2026-10-23T20:48:29Z",
  "published": "2026-10-23T20:48:29Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/strands-agents/harness-sdk/security/advisories/GHSA-4v6f-7vjh-6x4m"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-115419"
    },
    {
      "type": "WEB",
      "url": "https://github.com/strands-agents/harness-sdk/pull/2628"
    },
    {
      "type": "WEB",
      "url": "https://github.com/strands-agents/harness-sdk/pull/2696"
    },
    {
      "type": "WEB",
      "url": "https://github.com/strands-agents/harness-sdk/commit/398343faad0e485f2e441dab70355c9a52382537"
    },
    {
      "type": "WEB",
      "url": "https://github.com/strands-agents/harness-sdk/commit/403d87847e738e1c73909858d989cedcb67f0afa"
    },
    {
      "type": "WEB",
      "url": "https://github.com/strands-agents/harness-sdk/commit/f8ba9376fe4b8330d526b6480b47c4440150e0cd"
    },
    {
      "type": "WEB",
      "url": "https://aws.amazon.com/security/security-bulletins/2026-146-aws"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/strands-agents/harness-sdk"
    },
    {
      "type": "WEB",
      "url": "https://github.com/strands-agents/harness-sdk/releases/tag/python/v1.43.0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/strands-agents/harness-sdk/releases/tag/typescript/v1.5.0"
    },
    {
      "type": "WEB",
      "url": "https://pypi.org/project/strands-agents/1.43.0"
    },
    {
      "type": "WEB",
      "url": "https://www.npmjs.com/package/@strands-agents/sdk/v/1.5.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Strands Agents SDK: Exposure of data element to wrong session in the A2A Server"
}

CVE-2026-115419 (GCVE-0-2026-115419)

Vulnerability from cvelistv5 – Published: 2026-10-22 20:04 – Updated: 2026-10-22 20:04

Title

Unintended disclosure of data element to wrong session in Strands Agents SDK A2A Server

Summary

The A2A server component in Amazon Strands Agents SDK for Python before 1.43.0 and Amazon Strands Agents SDK for TypeScript before 1.5.0 does not properly isolate conversation state between callers. An authenticated remote user could read other tenants' conversation history and add persistent instructions that alter model behavior for subsequent callers via HTTP requests to the A2A endpoint using a different context_id. To mitigate this issue, users should upgrade to strands-agents 1.43.0 (Python) or @strands-agents/sdk 1.5.0 (TypeScript).

Severity

8.1 (High)


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

8.6 (High)


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

CWE

CWE-488 - Exposure of data element to wrong session

Assigner

AMZN CNA under the mitre root

CNA scorecard A 94/100 over 144 records in the last 180 days details

References

4 references

URL	Tags
https://pypi.org/project/strands-agents/1.43.0/	release-notespatch
https://www.npmjs.com/package/@strands-agents/sdk…	release-notespatch
https://aws.amazon.com/security/security-bulletin…	vendor-advisory
https://github.com/strands-agents/harness-sdk/sec…	third-party-advisory

Impacted products

2 products

Vendor	Product	Version
AWS	strands-agents	Affected: 0 , < 1.43.0 (custom) cpe:2.3:a:aws:strands-agents::::::::
AWS	strands-agents/sdk	Affected: 0 , < 1.5.0 (custom) cpe:2.3:a:aws:strands-agents_sdk::::::::

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "strands-agents",
          "vendor": "AWS",
          "versions": [
            {
              "lessThan": "1.43.0",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "strands-agents/sdk",
          "vendor": "AWS",
          "versions": [
            {
              "lessThan": "1.5.0",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:aws:strands-agents:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "1.43.0",
                  "versionStartIncluding": "0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            },
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:aws:strands-agents_sdk:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "1.5.0",
                  "versionStartIncluding": "0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ],
          "operator": "OR"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eThe A2A server component in Amazon Strands Agents SDK for Python before 1.43.0 and Amazon Strands Agents SDK for TypeScript before 1.5.0 does not properly isolate conversation state between callers. An authenticated remote user could read other tenants\u0027 conversation history and add persistent instructions that alter model behavior for subsequent callers via HTTP requests to the A2A endpoint using a different context_id.\u003c/p\u003e\u003cp\u003eTo mitigate this issue, users should upgrade to strands-agents 1.43.0 (Python) or @strands-agents/sdk 1.5.0 (TypeScript).\u003c/p\u003e"
            }
          ],
          "value": "The A2A server component in Amazon Strands Agents SDK for Python before 1.43.0 and Amazon Strands Agents SDK for TypeScript before 1.5.0 does not properly isolate conversation state between callers. An authenticated remote user could read other tenants\u0027 conversation history and add persistent instructions that alter model behavior for subsequent callers via HTTP requests to the A2A endpoint using a different context_id.\n\n\n\nTo mitigate this issue, users should upgrade to strands-agents 1.43.0 (Python) or @strands-agents/sdk 1.5.0 (TypeScript)."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-60",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-60 Reusing Session IDs (aka Session Replay)"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
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          ]
        },
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.6,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "LOW",
            "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:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
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        }
      ],
      "problemTypes": [
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          "descriptions": [
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              "cweId": "CWE-488",
              "description": "CWE-488 Exposure of data element to wrong session",
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      "providerMetadata": {
        "dateUpdated": "2026-10-22T20:04:04.191Z",
        "orgId": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
        "shortName": "AMZN"
      },
      "references": [
        {
          "tags": [
            "release-notes",
            "patch"
          ],
          "url": "https://pypi.org/project/strands-agents/1.43.0/"
        },
        {
          "tags": [
            "release-notes",
            "patch"
          ],
          "url": "https://www.npmjs.com/package/@strands-agents/sdk/v/1.5.0"
        },
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://aws.amazon.com/security/security-bulletins/2026-146-aws/"
        },
        {
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://github.com/strands-agents/harness-sdk/security/advisories/GHSA-4v6f-7vjh-6x4m"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Unintended disclosure of data element to wrong session in Strands Agents SDK A2A Server",
      "x_generator": {
        "engine": "Vulnogram 0.5.0"
      }
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  },
  "cveMetadata": {
    "assignerOrgId": "ff89ba41-3aa1-4d27-914a-91399e9639e5",
    "assignerShortName": "AMZN",
    "cveId": "CVE-2026-115419",
    "datePublished": "2026-10-22T20:04:04.191Z",
    "dateReserved": "2026-10-22T13:19:51.802Z",
    "dateUpdated": "2026-10-22T20:04:04.191Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

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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.
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