CVE-2026-56003
A heap buffer overflow due to missing size checking in the property buffer when parsing PCF files in libXfont2 ComputeScaledProperties() before libXfont2 before 2.0.8 could be used by attackers using authenticated X clients to execute code within the X…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.40%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A heap buffer overflow due to missing size checking in the property buffer when parsing PCF files in libXfont2 ComputeScaledProperties() before libXfont2 before 2.0.8 could be used by attackers using authenticated X clients to execute code within the X server.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.40% probability · 34th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-122
- Affected
- x/libxfont
- Source
- meissner@suse.de
References
- https://gitlab.freedesktop.org/xorg/lib/libxfont/-/commit/dff957a5158da038a282a59a31fe736702732939Patch
- https://www.openwall.com/lists/oss-security/2026/07/08/1Mailing List, Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.