{"id":"CVE-2026-79921","aliases":["GHSA-6c5v-hqjr-5xxp","GO-2026-6372"],"url":"https://o3.security/vulnerability/CVE-2026-79921","summary":"amqp091-go has a Potential Memory Exhaustion/Protocol Violation via Broker-Controlled Oversized Payload","details":"**Summary**\nA vulnerability exists in the amqp091-go client library where a compromised or malicious AMQP broker can force the client to allocate resources for and process content body frames that exceed the negotiated frame_max limit. This can lead to unexpected memory consumption or application-layer denial of service (DoS), bypassing the protocol's built-in framing constraints.\n\n**Details**\nDuring a standard AMQP 0-9-1 connection handshake, the client and the broker negotiate a maximum frame size (frame_max), for example, 4096 bytes.\n\nHowever, after negotiation, a malicious broker can send a valid basic.deliver sequence containing a content body frame whose header declares a payload size larger than the negotiated frame_max. Instead of enforcing the agreed-upon limit and closing the connection with a frame-error (as mandated by the AMQP 0-9-1 specification), the amqp091-go client:\n\n1. Accepts the broker-declared oversized frame size.\n2. Allocates memory based on this oversized declaration.\n3. Reads the payload, assembles it into the message, and delivers it to the consumer.\n\n**Impact**\n\n- Denial of Service (DoS): If a broker sends extremely large frame sizes, it can trigger significant memory allocations on the client side, potentially leading to Out-Of-Memory (OOM) crashes.\n- Protocol Violation: The client fails to enforce negotiated connection parameters, trusting the broker implicitly even after constraints have been established.","published":"2026-08-26T20:24:58.115Z","modified":"2026-09-27T18:26:46.093077049Z","cvss":null,"epss":{"score":0.00316,"percentile":0.24604,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/rabbitmq/amqp091-go","fixedVersion":"1.13.0"}],"fix":{"url":"https://github.com/rabbitmq/amqp091-go/commit/6beb7b51f59e46ddcf8066ad498dad32491d3be0","label":"rabbitmq/amqp091-go@6beb7b5"},"references":[{"type":"WEB","url":"https://github.com/rabbitmq/amqp091-go/releases/tag/v1.13.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/79xxx/CVE-2026-79921.json"},{"type":"ADVISORY","url":"https://github.com/rabbitmq/amqp091-go/security/advisories/GHSA-6c5v-hqjr-5xxp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-79921"},{"type":"FIX","url":"https://github.com/rabbitmq/amqp091-go/commit/6beb7b51f59e46ddcf8066ad498dad32491d3be0"},{"type":"FIX","url":"https://github.com/rabbitmq/amqp091-go/pull/353"},{"type":"PACKAGE","url":"https://github.com/rabbitmq/amqp091-go"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-27T18:26:46.093077049Z"}}