CVE-2026-121809: elixir-grpc grpc_server · Uncontrolled Resource Consumption
Affects elixir-grpc grpc_serverSource CVE Database V5
Not known to be exploited · CVSS 8.2 High : upgrade to 1.1.0 soon.
Data as of 13 Nov 2026, 16:35 UTC
Thin evidence
One scorer or none| CNA (EEF) | CVSS 4.0 | 8.2 |
|---|
- Patch
- Available – fixed in 1.1.0, 38955f1392cbf08eef231a347348445410455c85, 1.0.0 +1
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 13 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| elixir-grpcgrpc_server | Affected
| Fixed in
|
| grpc_serverelixir-grpc/grpc | Affected
| Fixed in
|
| elixir-grpcgrpc | Affected
| Fixed in
|
| grpcelixir-grpc/grpc | Affected
| Fixed in
|
Hexgrpc_serverpkg:hex/grpc_serverOther threats | Affected
| Fixed in
|
Hexgrpcpkg:hex/grpcOther threats | Affected
| Fixed in
|
CPE configurations (2)
cpe:2.3:a:elixir-grpc:grpc_server:*:*:*:*:*:*:*:*cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in grpc_server version 1.1.0 and grpc version 1.0.0. Users should upgrade to these versions or later to remediate the vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Description
CVE-2026-121809 is a high-severity vulnerability in elixir-grpc's grpc_server and grpc components. It involves an infinite loop caused by an unreachable exit condition in the GRPC.Server.Adapters.Cowboy.read_stream/1 function. This flaw allows unauthenticated attackers to indefinitely occupy a BEAM scheduler by sending a client-streaming or bidirectional-streaming request with a body that ends inside a gRPC message. The issue affects grpc_server versions from 1.0.0 up to but not including 1.1.0 and grpc versions from 0.3.1 up to but not including 1.0.0. Fixed versions are available.
References
- github.com/elixir-grpc/grpc/security/advisories/GHSA-c2h9-f9cc-27xh (opens in a new tab)
- cna.erlef.org/cves/CVE-2026-121809.html (opens in a new tab)
- osv.dev/vulnerability/EEF-CVE-2026-121809 (opens in a new tab)
- github.com/elixir-grpc/grpc/commit/0332faae5f5e132314794dbfdae5edecbccea292 (opens in a new tab)
- github.com/elixir-grpc/grpc/commit/38955f1392cbf08eef231a347348445410455c85 (opens in a new tab)
- github.com/elixir-grpc/grpc/commit/6d8a09ad919e208fb600538ac8b19bd733a04310 (opens in a new tab)