projectdiscovery/nuclei · error

could not write to temp secrets file: %w

Error message

could not write to temp secrets file: %w

What it means

The temp file was created but tempFile.Write(secretsData) failed (cmd/nuclei/main.go:913); the file is closed and removed before returning. Write failures on a freshly created temp file are almost always environmental — ENOSPC (disk/tmpfs full), EDQUOT (quota exceeded), or short writes — since permissions were already exercised at create time.

Source

Thrown at cmd/nuclei/main.go:913

	}

	tempDir := filepath.Join(os.TempDir(), "nuclei-secrets")
	if err := os.MkdirAll(tempDir, 0700); err != nil {
		return "", fmt.Errorf("could not create temp directory: %w", err)
	}

	tempFile, err := os.CreateTemp(tempDir, "inline-secrets-*.yaml")
	if err != nil {
		return "", fmt.Errorf("could not create temp secrets file: %w", err)
	}
	defer func() {
		_ = tempFile.Close()
	}()

	if _, err := tempFile.Write(secretsData); err != nil {
		_ = tempFile.Close()
		_ = os.Remove(tempFile.Name())
		return "", fmt.Errorf("could not write to temp secrets file: %w", err)
	}

	options.SecretsFile = append(options.SecretsFile, tempFile.Name())
	return tempFile.Name(), nil
}

View on GitHub (pinned to 265b3a3dec)

Solutions

1. Free space on the temp filesystem or point TMPDIR at a larger volume
2. Check quotas (`quota -s`) if enforced
3. Move inline secrets to a standalone secrets file outside the temp path
4. Pre-check free space in automation before launching scans

Example fix

# before
df -h /tmp   # 100% used

# after
TMPDIR=/data/tmp nuclei -profile scan.yaml

// pre-flight: verify writable space on the temp filesystem
var st syscall.Statfs_t
if err := syscall.Statfs(tempDir, &st); err == nil && st.Bavail*uint64(st.Bsize) < uint64(len(secretsData))*4 {
    return errors.New("insufficient space in temp dir for secrets file")
}

if _, err := tempFile.Write(secretsData); err != nil {
    _ = os.Remove(tempFile.Name())
    return fmt.Errorf("writing secrets to %s failed (disk full/quota?): %w", tempFile.Name(), err)
}

When it happens

Trigger: /tmp (often tmpfs) exhausted by large scans or other processes; per-user disk quota hit; container writable layer too small.

Common situations: Disk-full CI runners; containers with a small tmpfs /tmp; long scans with inline profile secrets on space-constrained boxes.

Related errors

• could not create temp directory: %w
• could not read profile file: %w
• could not create temp secrets file: %w
• Invalid protocol type: {valueToMap}
• invalid workflow with no templates or tags

AI-assisted analysis of projectdiscovery/nuclei@265b3a3dec (2026-08-15). Data as JSON: /api/errors/10d0809658a7db4b. Report an issue: GitHub.