diff --git a/cybersandbox/Dockerfile b/cybersandbox/Dockerfile
index 737077c..c865b52 100644
--- a/cybersandbox/Dockerfile
+++ b/cybersandbox/Dockerfile
@@ -14,7 +14,7 @@ FROM ghcr.io/agent-infra/sandbox@sha256:e0d7cfed24b373850f5f3df64439e9fcaa17e681
 # Stage 1: Go tools builder
 # ══════════════════════════════════════════════════════════════
 # golang 1.25-bookworm — picks up fixed stdlib for CVE-2025-68121 (crypto/tls).
-FROM golang@sha256:5f3787b7f902c07c7ec4f3aa91a301a3eda8133aa32661a3b3a3a86ab3a68a36 AS go-builder
+FROM golang@sha256:313faae491b410a35402c05d35e7518ae99103d957308e940e1ae2cfa0aac29b AS go-builder
 
 RUN apt-get update && apt-get install -y --no-install-recommends libpcap-dev \
  && rm -rf /var/lib/apt/lists/*