Loading vulnerability…
CVE-2026-56003 is a heap buffer overflow vulnerability in libXfont2 affecting versions prior to 2.0.8. The flaw is in ComputeScaledProperties() while parsing PCF font data. The function allocates a fixed-size property buffer of 70 slots and then writes property entries derived from source font properties without enforcing bounds checks. Matching properties can consume one slot for unscaled entries or two slots for scaledX or scaledY entries, allowing a crafted PCF font with excessive or duplicated properties to overrun the heap allocation. Because the parser does not adequately constrain the number of properties written into the buffer, malformed PCF fonts can corrupt heap memory during font processing within the X server font handling path.
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
What an attacker gets, and what they’ve been doing with it.
If you can’t patch tonight, do this now.
Patch, then assume compromise.
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
9 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A heap buffer overflow in libXfont2's ComputeScaledProperties() when parsing PCF files, caused by missing size checks in the property buffer. It may allow authenticated X clients to execute code within the X server.
One of three vulnerabilities fixed in libXfont 2.0.8 related to processing PCF font files.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.