The GNU C Library security advisories update for 2026-09-14
glibc advisory GLIBC-SA-2026-0017 discloses a buffer overflow in strfmon/strfmon_l affecting versions 2.38 through 2.44.
The GNU C Library published security advisories including GLIBC-SA-2026-0017, a buffer overflow in strfmon and strfmon_l. Calling these functions with right-justified width padding conversions can write past the end of the caller-supplied output buffer in glibc 2.38 to 2.44. Exploitation requires an application code path that calls strfmon with attacker-influenced parameters.
GNU GRUB 2.14: serial-MMIO lockdown bypass in Canonical-signed gcdx64.efi
Canonical-signed GRUB2 serial command accepts arbitrary MMIO addresses, letting local attackers with grub.cfg control bypass Secure Boot lockdown.
A vulnerability in Canonical's grub-efi-amd64-signed (gcdx64.efi, GRUB 2.14) exposes a serial command that accepts a caller-supplied 64-bit MMIO base address. The lockdown path does not restrict this command even when lockdown=y under UEFI Secure Boot, and the serial implementation does not validate that the requested register span belongs to a real UART rather than ordinary RAM. A local attacker with control of GRUB's boot configuration can abuse this to bypass the Secure Boot lockdown.