CVE-2026-124279
Streaming request body limit enforced only after an 8 MB read in elixir-grpc grpc_server
- High 8.2
Description
Allocation of Resources Without Limits or Throttling vulnerability in elixir-grpc grpc_server allows unauthenticated attackers to exhaust server memory via client-streaming or bidirectional-streaming requests. The streaming read clause of GRPC.Server.Adapters.Cowboy.Handler.info/3 (grpc_server/lib/grpc/server/adapters/cowboy/handler.ex) asks Cowboy for up to 8,000,000 bytes per read and compares the running total with max_body_size only after the read returns. The gRPC length prefix of a message is not checked before the message is buffered. Each stream can therefore buffer up to one full read beyond the configured limit before it is refused, and many concurrent streams exhaust node memory. Releases before 1.0.6 apply no limit to streaming requests at all. This issue affects grpc_server: from 1.0.0 before 1.1.0.
Key facts
- Published
- 13 Nov 2026
- Last changed
- 13 Nov 2026
- Assigned by
- EEF
- EPSS
- 0.49% likely to be exploited in the next 30 days, higher than 42.688% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: none; Automatable: no; Technical impact: partial
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 8.2CVSS 4.0, Highfrom the CNA (EEF)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
An unauthenticated client that opens many streaming calls can make the server buffer more request data than its configured limit allows and crash the node, taking down every service on it. (CNA impact statement)
No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| elixir-grpc | grpc_server |
|
| elixir-grpc | grpc_server |
|
Timeline
- 13 Nov 2026 Published