# Dell BIOS Passwords: Weak XOR Encryption Vulnerability Security flaw allows password recovery from SPI Flash. - **Source:** [Technical Information Security Content & Discussion](https://brifing.si/source/00707f34-d14e-4e4d-a6f0-2cd451bd38f7) - **Published:** 2026-07-13 - **Topic:** [Software & Engineering](https://brifing.si/c/engineering) - **Original article:** - **On Brifing:** https://brifing.si/s/5858bb97-e25f-46f9-917e-8404d7a743f4 ## Discovery of the Vulnerability The XOR encryption method used in Dell BIOS passwords has been found to be weak. This flaw allows passwords to be recovered from SPI Flash memory. ## CVE-2026-40639 Recorded as CVE-2026-40639, this security vulnerability affects the BIOS password protection mechanism in Dell computers. The flaw can lead to easy decryption of passwords. ## Recovery via SPI Flash The recovery of BIOS passwords from SPI Flash memory is the most critical outcome of this security flaw. This method allows passwords to be easily compromised. ## Weakness in XOR Encryption The XOR encryption method has proven to be insufficient for security. This weakness makes it difficult to protect passwords and increases security risks. ## Dell's Response Dell has initiated efforts to address this security vulnerability. The company aims to strengthen the BIOS encryption mechanism. ## Importance for Users This security vulnerability poses a significant risk for Dell users. Protecting BIOS passwords is crucial for system security. ## Sources covering this story - https://www.reddit.com/r/netsec/comments/1uv6qbn/dell_bios_passwords_weak_xor_encryption_allows/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._