{"cve":"CVE-2026-111761","nvd":{"published":"2026-10-20T15:17:11.823","modified":"2026-10-22T22:18:01.230","status":"Awaiting Analysis","description":"A2A Java SDK is the official Java SDK for the Agent2Agent (A2A) Protocol. Prior to 1.3.0.Final, BasePushNotificationSender in server-common sends task data to the URL in TaskPushNotificationConfig without destination validation, scheme restrictions, or bounds on redirects. InMemoryPushNotificationConfigStore.setInfo stores the URL verbatim, and onCreateTaskPushNotificationConfig does not validate the destination. In the default deployment with push notifications enabled, an unauthenticated caller can register a destination through an inline SendMessage configuration or CreateTaskPushNotificationConfig for an existing task, causing task status and artifact updates to send requests from the server's network position to loopback, private, link-local cloud-metadata, IPv6 unique-local, unspecified, or multicast destinations where routing permits. JdkA2AHttpClient and VertxA2AHttpClient follow redirects, allowing a webhook redirect to bypass creation-time destination checks and convert a POST into a GET; hostname-only checks also do not prevent DNS rebinding. Direct POST delivery can push attacker-influenced task data into internal services, whereas a redirected POST-to-GET request drops the body. The sender discards the fetched response and does not expose delivery success or failure, so the demonstrated behavior does not provide response read-back. No credentials or user interaction are required. This issue is fixed in version 1.3.0.Final.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","score":5.8},"cwes":["CWE-918"],"references":["https://github.com/a2aproject/a2a-java/commit/b855b2ae37e4bf23f73e7746ce166fbc5a0b8b5b","https://github.com/a2aproject/a2a-java/pull/1096","https://github.com/a2aproject/a2a-java/releases/tag/v1.3.0.Final","https://github.com/a2aproject/a2a-java/security/advisories/GHSA-q78c-5jjq-57g8","https://github.com/a2aproject/a2a-java/security/advisories/GHSA-q78c-5jjq-57g8"],"products":[],"source":"nvd","synced_at":"2026-10-23T16:39:26.291718493+00:00"},"epss":{"cve":"CVE-2026-111761","score":0.00586,"percentile":0.47719,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-q78c-5jjq-57g8","url":"https://osv.dev/vulnerability/GHSA-q78c-5jjq-57g8","summary":"A2A Java SDK has Server-Side Request Forgery (SSRF) in push-notification delivery","modified":"2026-10-20T21:15:04.059690010Z","packages":[{"ecosystem":"Maven","name":"org.a2aproject.sdk:a2a-java-sdk-server-common","purl":"pkg:maven/org.a2aproject.sdk/a2a-java-sdk-server-common","ranges":["<1.3.0.Final"],"fixed":["1.3.0.Final"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}