CVE-2023-39950
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk30th percentile - higher than 30% of all known CVEs
Summary
The vulnerability in efibootguard arises from insufficient validation and sanitization of input from untrusted bootloader environment files, which can lead to crashes and potential code injections. This issue occurs when attempting to modify a manipulated environment, particularly user variables.
Risk Assessment
The organization may be exposed to system crashes and the possibility of malicious code injection, which could lead to data loss or system takeover. Unpatched components may pose a significant security threat.
Recommendation
It is recommended to update the efibootguard library and tools to version v0.15, which contains patches to sanitize and validate the bootloader environment. Avoid modifying user variables if using an unpatched version of efibootguard.
Related vulnerabilities
- CVE-2026-96659Critical
A flaw in Foreman allows an authenticated user with low-level Viewer permissions to cause unauthorized information disclosure by submitting requests to template preview endpoints. The user can access sensitive data such as host root passwords. Under insecure configurations with Safemode disabled, the flaw may also allow arbitrary command execution as the Foreman system account.
- CVE-2026-96658Critical
A flaw in Foreman allows an authenticated attacker with low-level permissions to achieve remote code execution (RCE) by bypassing the Safemode sandbox within the templating engine. Due to improper handling of delegated methods, the attacker can append unauthorized functions to the allowed execution list, enabling arbitrary command execution on the hosting server.
- CVE-2026-13043Critical
The Kernel Memory Access Driver (PSKMAD) used by WatchGuard endpoint security products does not properly enforce authentication. A local, authenticated attacker can bypass the driver's access-control handshake and issue arbitrary privileged commands to the driver, resulting in disclosure of kernel and process memory.
- CVE-2026-94620Critical
Classroom 50 prior to version 1.11.0, when running `gh teacher download`, clones each student's assignment repository and then writes autograde artifacts (`result.json` and `results.json`) into the just-cloned working tree. The write followed symlinks, so a student who committed `result.json` or `results.json` as a symlink could redirect the teacher's write to an arbitrary path (e.g. `~/.zshrc`, `~/.ssh/authorized_keys`, a cron file, or an in-clone `.git/hooks/*` file), with attacker-controlled bytes. This is an arbitrary file write leading to code execution as the teacher, whose `gh` token carries `admin:org`, `repo`, and `workflow` across the entire classroom organization.
- CVE-2026-12627Critical
Fortra's Core Privileged Access Manager (BoKS) contains a stack-based buffer overflow vulnerability in boks_autoregisterd. A remote attacker with network access to the autoregistration service may be able to trigger memory corruption during client response processing.
- CVE-2026-79898Critical
Fortra BoKS Manager contains a command injection vulnerability in crlserver. An authenticated user authorized to add CRL URLs through BCC, the WSI REST or SOAP API, or the cacrl command-line interface could cause shell command substitution to be processed by crlserver as root on the BoKS Master.
- CVE-2026-62071Critical
The WordPress File Upload plugin in versions up to and including 5.1.10 contains an SQL injection vulnerability exploitable by an unauthenticated attacker.
- CVE-2026-103752Critical
The Authorizer plugin in versions up to and including 3.15.3 contains an unauthenticated privilege escalation vulnerability.
- CVE-2026-79901Critical
In deployments using BoKS keytab management, affected versions of boks_keytabmd generate Active Directory service-account passwords from a predictable pseudo-random sequence seeded with the current Unix timestamp. An attacker who knows the service principal and can estimate the password-change time can reproduce a limited candidate set and verify candidates offline.
- CVE-2026-103264Critical
Fleet versions before 4.87.0 contain an authentication bypass vulnerability in the device API that accepts hostnames and hardware serials as authentication tokens in addition to device UUIDs. Unauthenticated attackers who know or guess these non-secret identifiers can authenticate as iOS/iPadOS hosts to read device data and trigger device-scoped actions including software installation and MDM migration.
Original NVD description (English source)
efibootguard is a simple UEFI boot loader with support for safely switching between current and updated partition sets. Insufficient or missing validation and sanitization of input from untrustworthy bootloader environment files can cause crashes and probably also code injections into `bg_setenv`) or programs using `libebgenv`. This is triggered when the affected components try to modify a manipulated environment, in particular its user variables. Furthermore, `bg_printenv` may crash over invalid read accesses or report invalid results. Not affected by this issue is EFI Boot Guard's bootloader EFI binary. EFI Boot Guard release v0.15 contains required patches to sanitize and validate the bootloader environment prior to processing it in userspace. Its library and tools should be updated, so should programs statically linked against it. An update of the bootloader EFI executable is not required. The only way to prevent the issue with an unpatched EFI Boot Guard version is to avoid accesses to user variables, specifically modifications to them.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

