Vulnerability in github.com/rabbitmq/amqp091-go (CVE-2026-77403)
Summary
Vulnerability in github.com/rabbitmq/amqp091-go (CVE-2026-77403). Risk of unauthorized operations or information disclosure. Exploitable via FrameMax. Mitigation: upgrade to 1.13.0 or later.
Original description
The description as published by the source.
Summary
A Denial of Service (DoS) vulnerability exists in the AMQP client's connection negotiation logic. The AMQP specification explicitly mandates a strict minimum frame size of 4096 bytes to prevent pathological packet fragmentation. While the library defines a frameMinSize = 4096 constant, the connection negotiation loop fails to enforce this boundary, blindly accepting whatever maximum frame size (FrameMax) the server advertises during the handshake.
If a client connects to a malicious or compromised AMQP broker that advertises an extremely low FrameMax (such as 1 byte), the negotiation succeeds. Consequently, every subsequent message transmission is forced to splinter into thousands or millions of single-byte frames, causing massive CPU overhead, thread contention, and a near-instantaneous application freeze.
Vulnerability Details
Mechanism
During the connection establishment phase, the client and server negotiate connection parameters—including maximum channel count, heartbeat intervals, and maximum frame sizes. The vulnerability is located where the client accepts the server's tuning parameters:
// Connection negotiation logic maps server values directly without validation
if serverSettings.FrameMax > 0 {
// VULNERABILITY: Lacks a floor validation check against frameMinSize (4096)
c.config.FrameMax = serverSettings.FrameMax
}
Because there is no conditional check asserting that serverSettings.FrameMax >= frameMinSize, a v…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-77403 has been found in github.com/rabbitmq/amqp091-go.
Attackers can target a specific entry point like FrameMax over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade github.com/rabbitmq/amqp091-go to 1.13.0 or later.
If unsure, ask your IT team or search "github.com/rabbitmq/amqp091-go CVE-2026-77403" on the vendor's site.
CVE-2026-77403 (github.com/rabbitmq/amqp091-go) — CWE-770
Attack surface: FrameMax / connection.tune
Patched: 1.13.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-770) exists in github.com/rabbitmq/amqp091-go. Attackers reach the vulnerable code path via FrameMax.
Check the vendor advisory for the affected versions of github.com/rabbitmq/amqp091-go. Attack surface: FrameMax / connection.tune.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 1.13.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/rabbitmq/amqp091-go' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'github.com/rabbitmq/amqp091-go' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/rabbitmq/amqp091-goを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/rabbitmq/amqp091-go to 1.13.0ステージング環境で 1.13.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com