Your system information

• Steam client version (build number or date): 1785799196 (updater built Aug 3 2026)
• Distribution (e.g. Ubuntu): Linux Mint 22.3 Cinnamon
• Opted into Steam client beta?: No
• Have you checked for system updates?: Yes
• Steam Logs: [attach steam-logs.tar.gz here after running the tar command]
• GPU: AMD Radeon RX 5700 XT (RADV NAVI10), Mesa 25.2.8-0ubuntu0.24.04.2

Please describe your issue in as much detail as possible:

Expected: Steam client opens normally.

Actual: steamwebhelper crashes repeatedly (SIGSEGV) in libcef.so immediately after launch, so the Steam client window never renders. Confirmed via coredumpctl that it's a genuine segfault, not a clean exit. The crash backtrace shows the same address repeating dozens of times in the stack (infinite recursion / stack overflow pattern) inside libcef.so (CEF/Chrome 126.0.6478.183).

Things I've already tried that did NOT fix it:

• Reinstalling Steam completely (purge + reinstall via apt)
• Wiping ~/.local/share/Steam/config/htmlcache and moving aside ~/.steam and Steam/config entirely for a fresh config
• Testing on two different kernels (7.0.0-28-generic and 6.14.0-37-generic) — same crash on both
• Testing both the native .deb install and the Flatpak version — same crash on both
• -cef-disable-gpu, -cef-disable-gpu-compositing, -no-cef-sandbox, -no-sandbox, -cef-force-32-bit-swiftshader, -tenfoot
• LIBGL_ALWAYS_SOFTWARE=1, SDL_VIDEODRIVER=x11, STEAM_RUNTIME=0, GTK_MODULES=
• Reinstalling GTK2/GTK3 theme packages
• Checked for AppArmor denials (journalctl -k | grep apparmor) — none found
• Checked for GPU driver errors in kernel log at crash time — none found
• Confirmed toolkit-accessibility is off system-wide

Other apps that use GPU-accelerated rendering (OBS, Modrinth, Minecraft via Modrinth launcher, Discord) all work fine on this same system, so this appears isolated to Steam's specific bundled CEF build.

Steps for reproducing this issue:

1. Launch Steam (native install or Flatpak) on Linux Mint 22.3 with an AMD RX 5700 XT / Mesa 25.2.8
2. steamwebhelper starts, immediately segfaults in libcef.so
3. Steam automatically respawns steamwebhelper, which crashes again, repeating indefinitely (client window never appears)