VDB

CVE-2026-77403

CVE-2026-77403 PUBLISHED CVSS 8.899999618530273 HIGH

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. ---

EPSS 0.52% · 44.4th percentile

Risk Scores

CVSS 4.0
8.899999618530273
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
EPSS Score
0.52%
44.4th percentile

Affected Products

VendorProductVersions
github.comrabbitmq/amqp091-go0
rabbitmqamqp091-go0

Timeline

  • Sep 16, 2026 Coalition ESS Score
  • Sep 16, 2026 CVE Published
  • Sep 17, 2026 CVE Updated
  • Sep 17, 2026 EPSS Score
  • Sep 18, 2026 EPSS Score
  • Sep 24, 2026 EPSS Score
  • Sep 26, 2026 EPSS Score
  • Sep 30, 2026 EPSS Score
  • Oct 2, 2026 EPSS Score
  • Oct 6, 2026 EPSS Score
  • Oct 8, 2026 EPSS Score
  • Oct 11, 2026 EPSS Score
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