Undici v6.24.0 Security Release Notes (LTS)

This release backports fixes for security vulnerabilities affecting the v6 line.

Upgrade guidance

All users on v6 should upgrade to v6.24.0 or later.

Fixed advisories

• GHSA-2mjp-6q6p-2qxm / CVE-2026-1525 (Medium)
  Inconsistent interpretation of HTTP requests (request/response smuggling class issue).

• GHSA-f269-vfmq-vjvj / CVE-2026-1528 (High)
  Malicious WebSocket 64-bit frame length handling could crash the client.

• GHSA-4992-7rv2-5pvq / CVE-2026-1527 (Medium)
  CRLF injection via the upgrade option.

• GHSA-v9p9-hfj2-hcw8 / CVE-2026-2229 (High)
  Unhandled exception from invalid server_max_window_bits in WebSocket permessage-deflate negotiation.

• GHSA-vrm6-8vpv-qv8q / CVE-2026-1526 (High)
  Unbounded memory consumption in WebSocket permessage-deflate decompression.

Not applicable to v6

• GHSA-phc3-fgpg-7m6h / CVE-2026-2581 affects >= 7.17.0 < 7.24.0 only.

Affected and patched ranges (v6)

• CVE-2026-1525: affected < 6.24.0, patched 6.24.0
• CVE-2026-1528: affected >= 6.0.0 < 6.24.0, patched 6.24.0
• CVE-2026-1527: affected < 6.24.0, patched 6.24.0
• CVE-2026-2229: affected < 6.24.0, patched 6.24.0
• CVE-2026-1526: affected < 6.24.0, patched 6.24.0

References

• GitHub Security Advisories: https://github.com/nodejs/undici/security/advisories
• NVD CVE-2026-1525: https://nvd.nist.gov/vuln/detail/CVE-2026-1525
• NVD CVE-2026-1528: https://nvd.nist.gov/vuln/detail/CVE-2026-1528
• NVD CVE-2026-1527: https://nvd.nist.gov/vuln/detail/CVE-2026-1527
• NVD CVE-2026-2229: https://nvd.nist.gov/vuln/detail/CVE-2026-2229
• NVD CVE-2026-1526: https://nvd.nist.gov/vuln/detail/CVE-2026-1526