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CVE-2026-9983 is a high-severity type confusion vulnerability discovered in Skia, the open-source 2D graphics library developed by Google and used extensively within the Chrome browser for graphics rendering. The vulnerability affects all Google Chrome versions prior to 148.0.7778.216. It allows a remote, unauthenticated attacker to execute arbitrary code inside the browser’s sandbox by convincing a user to visit a specially crafted HTML page.
The technical root of this vulnerability lies in improper type handling within the Skia graphics processing pipeline, specifically within the `SkOpCoincidence` class. This class manages linked lists of graphical objects. The flaw manifests in functions such as release(), fixUp(), and markCollapsed(), which manipulate the `fHead` and `fTop` linked-list head pointers. These functions were found to pass pointers by value, modifying global state directly. When the head element of the linked list is released from memory, subsequent operations continue to use the old, already-freed head pointer for linked-list traversal. This creates a use-after-free (UAF) condition stemming from the initial type confusion—the program incorrectly treats a freed memory region as a valid object of the expected type.
An attacker can exploit this by crafting an HTML page with malicious graphics data that triggers this flawed logic during the rendering process. By manipulating object pointers and memory locations in ways that violate expected type constraints, the attacker can achieve arbitrary code execution within the Chrome sandbox. The vulnerability is classified under CWE-843 (Access of Resource Using Incompatible Type). The fix implemented by Google addresses the underlying type validation by changing the function signatures from `SkCoincidentSpans head` to SkCoincidentSpans headPtr. This modification ensures that functions can correctly update the linked-list head node via pointer references, preventing access to invalid pointers after they have been freed.
DailyCVE Form:
Platform: Chrome Browser
Version: < 148.0.7778.216
Vulnerability: Type Confusion (UAF)
Severity: High (CVSS 8.8)
date: May 28, 2026
Prediction: Patch already available (148.0.7778.216)
What Undercode Say:
Analytics show this vulnerability targets the Skia graphics library’s memory management. The exploit chain requires user interaction (visiting a malicious page). No public proof-of-concept has been observed. The CVSS vector is AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. The vulnerability affects Windows, macOS, and Linux platforms.
Check current Chrome version
google-chrome --version
Update Chrome on Debian/Ubuntu
sudo apt update && sudo apt install --only-upgrade google-chrome-stable
Update Chrome on RHEL/CentOS/Fedora
sudo dnf update google-chrome-stable
Verify update applied (should be 148.0.7778.216 or later)
google-chrome --version
Check if system is vulnerable (version comparison)
CHROME_VER=$(google-chrome --version | awk '{print $3}')
if [[ "$CHROME_VER" < "148.0.7778.216" ]]; then
echo "VULNERABLE: Update Chrome immediately"
else
echo "Patched: Version $CHROME_VER is secure"
fi
Debian Chromium package status
apt-cache policy chromium-browser
Snap-based Chromium (Ubuntu 19.10+)
snap info chromium
Exploit: (Educational Purposes!)
The exploitation process targets the Skia `SkOpCoincidence` class. When processing malicious HTML with crafted SVG or canvas elements, the `release()` function frees a linked-list head node. The `fixUp()` function then attempts to traverse the list using the stale `fHead` pointer. This UAF condition allows an attacker to spray memory with controlled data, replacing the freed object with a fake vtable or function pointer. When the browser calls a method on the corrupted object, control is transferred to attacker-controlled shellcode. The exploit achieves remote code execution within the renderer process sandbox. Successful exploitation can lead to further sandbox escape attempts via kernel or system-level vulnerabilities.
Protection:
- Immediately update Google Chrome to version 148.0.7778.216 or later
- Enable automatic browser updates to ensure timely patching
- Exercise caution when visiting untrusted websites
- Consider implementing browser security policies that restrict access to untrusted content
- For Ubuntu users, the `chromium-browser` snap package is automatically updated
- Monitor vendor advisories from Google Chrome Releases
Impact:
Successful exploitation allows a remote attacker to execute arbitrary code within the Chrome sandbox with the privileges of the browser process. This can lead to complete compromise of the affected system, including unauthorized access to sensitive data, installation of malware, and further lateral movement within the network. The vulnerability requires no special privileges and can be triggered simply by visiting a malicious webpage. The CVSS base score of 8.8 (High) reflects the significant risk posed by this flaw.
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Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
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