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CVE-2026-59679 on Cyberus Linux 26.05

Aliases: CVE-2026-59679

Packages: libxfont_2

Status: Resolved

Advisory Information

fs_read_glyphs() in the libXfont2 font-server client (src/fc/fserve.c) indexes the per-character encoding[] array using num_chars from the FS_QueryXBitmaps16 reply, but that array was allocated with a size derived from num_extents in the separate FS_QueryXExtents16 reply. The two CARD32 fields are never cross-checked. A malicious or compromised font server can send a small num_extents (e.g. 1) in the extents reply, then a large num_chars (e.g. 100000) in the bitmaps reply. This causes attacker-controlled out-of-bounds heap read and writes.

Updates

2026-09-03 23:08 CEST

Metadata changes:

  • Status for package libxfont_2: “Resolved” (c418cc929b3e42958856c17507e3206f2d948de8)

2026-08-12 17:27 CEST

Metadata changes:

  • Status for package libxfont_2: “In Progress” (c418cc929b3e42958856c17507e3206f2d948de8)

(Amended on: 2026-08-12 17:28 CEST)

2026-08-07 10:30 CEST

Metadata changes:

  • Status for package libxfont_2: “Plausible”

(Amended on: 2026-08-11 03:11 CEST)