CVE-2026-56958: gf_algo.c Information Disclosure Vulnerability

CVE-2026-56958 Overview

CVE-2026-56958 is an out-of-bounds read vulnerability in the gf_algo_get_cached_dump_data function of gf_algo.c, a component referenced in the Android Security Bulletin for September 2026. The flaw stems from a missing bounds check that allows a local, low-privileged process to read memory outside the intended buffer. Successful exploitation results in local information disclosure without requiring user interaction or additional execution privileges. The issue is tracked under [CWE-125: Out-of-bounds Read] and affects Android/Pixel components as documented by Google.

Critical Impact
A local attacker with low privileges can read adjacent memory contents, potentially exposing sensitive data processed by the affected component.

Affected Products

Android platform components referenced in the Pixel security bulletin
gf_algo.c implementation containing gf_algo_get_cached_dump_data
See the Android Security Bulletin September 2026 for the authoritative component and version list

Discovery Timeline

2026-09-15 - CVE-2026-56958 published to NVD
2026-09-16 - Last updated in NVD database

Technical Details for CVE-2026-56958

Vulnerability Analysis

The vulnerability resides in gf_algo_get_cached_dump_data, a function responsible for returning cached dump data from a buffer maintained by the gf_algo component. The function fails to validate an offset or length parameter against the actual size of the cached buffer before performing a read operation. As a result, memory beyond the allocated region can be returned to the caller.

The impact is limited to confidentiality. The vulnerability does not permit modification of memory or elevation of privileges by itself. However, disclosed memory contents may include cryptographic material, pointers useful for bypassing address space layout randomization (ASLR), or other sensitive state that supports follow-on attacks in an exploit chain.

Root Cause

The root cause is a missing bounds check [CWE-125]. The affected code path trusts a size or index value without verifying that the requested read stays within the allocated buffer. When the value exceeds the buffer size, the function reads adjacent heap or stack memory and returns it to the caller.

Attack Vector

Exploitation requires local access with low privileges and does not require user interaction. An attacker with the ability to invoke the affected interface, such as a malicious application already installed on the device, can trigger the vulnerable code path and receive out-of-bounds data through the normal return channel. No verified public proof-of-concept code is available at the time of publication. See the Android Security Bulletin September 2026 for the vendor's technical acknowledgement.

// No verified proof-of-concept code is available.
// Refer to the Android Security Bulletin for the technical fix reference.

Detection Methods for CVE-2026-56958

Indicators of Compromise

No public indicators of compromise have been published for this vulnerability.
Exploitation is unlikely to produce distinctive artifacts because the flaw is an information-disclosure primitive triggered through legitimate interface calls.

Detection Strategies

Inventory Android and Pixel devices to identify those running builds predating the September 2026 security patch level.
Review application permissions and installed packages for untrusted software capable of invoking privileged system interfaces.
Monitor for anomalous local access to vendor-specific components exposed by the affected build.

Monitoring Recommendations

Track the Android security patch level reported by managed devices through mobile device management (MDM) telemetry.
Alert on installation of applications requesting access to low-level device interfaces on outdated builds.
Correlate crash and diagnostic logs from the gf_algo component with unexpected process activity.

How to Mitigate CVE-2026-56958

Immediate Actions Required

Apply the September 2026 Android security patch level, or later, to all affected devices as it becomes available from the device vendor.
Restrict installation of untrusted third-party applications on impacted devices until patches are deployed.
Enforce MDM policies that verify patch level compliance before allowing access to sensitive enterprise resources.

Patch Information

The fix is included in the Android Security Bulletin September 2026. Device owners should install the security update corresponding to the 2026-09-01 patch level or later. OEM release timing varies; consult the device manufacturer for availability.

Workarounds

No vendor-supplied workaround has been published; the security patch is the authoritative remediation.
Reduce risk by limiting device use to trusted applications and enterprise-approved software sources.
Apply conditional access controls to restrict unpatched devices from sensitive corporate data.

bash

# Verify the Android security patch level on a connected device
adb shell getprop ro.build.version.security_patch