Yet another forever day

CVE-2026-97631 joins a long list of previously discovered vulnerabilities in UEFI or code that works closely with it. The most severe of them, LogoFail, stemmed from logo images included in the UEFI of just about every hardware maker. Rendering bugs allowed attackers to subvert the chain of trust UEFI enforces and go on to install malicious components before the OS loaded or Secure Boot ran. PixieFail was a vulnerability similar to CVE-2026-97631. It, too, was the result of faulty PXE boot flaws in EDK2. Following discovery of the vulnerability, researchers embarked on multiple fuzzing projects designed to surface other critical flaws in the open source code library. It appears those efforts failed to find this latest flaw.

Other recently discovered UEFI flaws include:

  • PKFail, a supply-chain failure resulting from non-production test platform keys, public for more than a decade before they were discovered, used in hundreds of device models
  • BootHole
  • Bootkit and
  • BlackLotus

Like CVE-2026-97631, exploitation or use of these payloads is appealing because it allows attackers to infect machines early in the boot process, before TPM and other defenses load, so they can inflict maximum damage. Given the ubiquity of CVE-2026-97631, Moore said it’s likely a “forever” bug that will live on in end-of-support systems.

There are important caveats and limitations to exploiting this latest vulnerability. As noted, some level of control over a local network is a prerequisite. That likely limits exploitation to insiders or attackers, such as nation-states or ransomware operators, who manage to gain low-level access inside a network and are looking for a way to elevate system rights. There’s no evidence yet that CVE-2026-97631 provides an initial entry point into a network. There are other hurdles to clear.

“For exploiting the vulnerability itself, an attacker needs to guess specific addresses within the target system, so it’s not something that you can throw a single exploit at any target and get RCE across a diverse range of devices, but it needs to be tuned for each target model/version/configuration since the addresses will change based on those,” Jesse Michael, a principal researcher at firmware security firm Eclypsium, told Ars. “Unlike some of the previous, high-profile vulnerabilities like BootHole, Black Lotus, and Baton Drop, this vulnerability can be fixed with a basic code fix, which will require deploying a BIOS/UEFI update, but they don’t need to deal with revocations, pk/kek/db/dbx key management updates, or making sure to update OS and provisioning media like you do with Secure Boot bypasses in the bootloader itself.”