CVE-2026-102477
8.7HighPublished 15 Oct 2026 · NVD status: Undergoing Analysis · AI triage by gemini-3.8-flash
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Impact
- High impact on availability
- Weakness
- CWE-409
Impact
Remote, unauthenticated attackers can crash gRPC endpoints with a denial-of-service via memory exhaustion. They only need network access to send a compressed gRPC payload to the server.
Root cause
The maximum message size check runs against raw compressed bytes rather than the uncompressed content, allowing compression bomb attacks to bypass memory limits.
Affected systems
io.vertx:vertx-grpc-server versions 4.0.0 through 4.5.34, 5.0.0 through 5.0.12, 5.1.0 through 5.1.9, and 5.2.0
CVSS v4.0 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Fix & remediation
Upgrade io.vertx:vertx-grpc-server dependencies past the affected ranges (to 4.5.35+, 5.0.13+, 5.1.10+, or 5.2.1+). If patching cannot happen immediately, restrict or disable decompression or limit request sizes at an upstream reverse proxy.
$ mvn dependency:tree -Dincludes=io.vertx:vertx-grpc-serverAI-suggested. Run it in staging first and check it against the vendor advisory. Why?
NVD description
In Eclipse Vert.x versions [4.0.0, 4.5.34] or [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], a gRPC endpoint does have a configurable per message maximum size in bytes, however the maximum size applies to the received bytes. When applied to a compressed message, this only applies to the compressed size and not the actual size of the uncompressed content. This can be used to force a gRPC endpoint to allocate more bytes than the value defined by the configuration, making the endpoint vulnerable to compression bomb attacks. The impacted component is io.vertx:vertx-gprc-server.