ZeroHour

CVE-2025-27363

KEVmass

Out-of-Bounds Write in FreeType Font Parsing Allows Arbitrary Code Execution

CISA: FreeType Out-of-Bounds Write Vulnerability

CVSS 3.1
8.1 high
EPSS
28%p98
Published
()
KEV added
AI analysis

FreeType, the widely bundled open-source font rendering library, contains an out-of-bounds write (CWE-787) when parsing subglyph structures in TrueType GX and variable font files. The flaw is triggered when an application using FreeType renders a specially crafted font file, such as one embedded in a document, webpage, or downloaded file. A successful exploit may allow the attacker to execute arbitrary code with the privileges of the application that processed the font. Because FreeType ships by default with virtually all major Linux distributions, Android, and many applications and embedded products, the affected population is extremely broad, though specific affected version ranges are not enumerated in the available data. The vulnerability was added to the CISA Known Exploited Vulnerabilities catalog on 2025-05-06, indicating confirmed in-the-wild exploitation, and carries a high EPSS probability of 27.8% (98th percentile); no public proof-of-concept code is known.

What to do: Update FreeType to the latest available release/commit and apply vendor patches for any product that bundles or depends on it, since exact vulnerable version ranges are not stated in the available data. Inventory your environment for software, operating systems, and dependencies that ship FreeType, and prioritize internet-facing or user-facing systems that process untrusted font files. Federal agencies must follow the CISA KEV required action (apply vendor mitigations per BOD 22-01) or discontinue use if mitigations are unavailable.

Affected
FreeType
Estimated exposure
masshundreds of millions to billions of devices (FreeType is the default font-rendering library bundled in major Linux distributions and Android) — FreeType is effectively ubiquitous as the font-rendering library shipped with most Linux distributions, Android, and countless third-party applications and embedded systems, so the installed base exceeds a billion devices even though only…

Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.

Description

An out of bounds write exists in FreeType versions 2.13.0 and below (newer versions of FreeType are not vulnerable) when attempting to parse font subglyph structures related to TrueType GX and variable font files. The vulnerable code assigns a signed short value to an unsigned long and then adds a static value causing it to wrap around and allocate too small of a heap buffer. The code then writes up to 6 signed long integers out of bounds relative to this buffer. This may result in arbitrary code execution. This vulnerability may have been exploited in the wild.

CISA Known Exploited Vulnerability
Affected
FreeType FreeType
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Due date
Ransomware use
Unknown
Vendors
freetypedebian
Products
freetype, debian linux
Weakness
CWE-787
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

In the news