CVSS 4.0
8.2 highCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NCVE-2026-124279 Streaming request body limit enforced only after an 8 MB read in elixir-grpc grpc_server
High (8.2) in elixir-grpc grpc server. Fixed in grpc_server 1.1.0.
On this page
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.
Severity
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: no · Technical impact: partial, assessed 2026-11-13. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-770 Allocation of Resources Without Limits or Throttling
- Published
- Modified
- Assigned by
- EEF (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| elixir-grpc grpc_server | from 1.0.0 before 1.1.0 |
Fix and patched versions
grpc_server(Hex): fixed in 1.1.0
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| EEF-CVE-2026-124279 | Hex | grpc_server | >=1.0.0 <1.1.0 | 1.1.0 |
| EEF-CVE-2026-124279 | v1.0.6, v1.0.3, v1.0.0 | no fix published |
Attack patterns (CAPEC)
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits. More on the page of CWE-770 (20).
References
- https://cna.erlef.org/cves/CVE-2026-124279.html
- https://github.com/elixir-grpc/grpc/commit/49e18c3ec6bb9afe2f712caad3dbab5c56a68a00
- https://github.com/elixir-grpc/grpc/commit/b1e771d558941b1ed4b6de8b39f6a5375543db01
- https://github.com/elixir-grpc/grpc/security/advisories/GHSA-736x-r87j-jhcm
- https://osv.dev/vulnerability/EEF-CVE-2026-124279