CVE-2026-11266 Overview
CVE-2026-11266 is a Safe Browsing bypass vulnerability in Google Chrome versions prior to 149.0.7827.53. The flaw stems from an inappropriate implementation in the Safe Browsing component, allowing a remote attacker to evade reputation-based file checks by serving a malicious file. Exploitation requires user interaction, such as downloading or opening the attacker-supplied file. Google classifies the Chromium security severity as Low, and the issue is tracked under [CWE-693] (Protection Mechanism Failure). The vulnerability affects Chrome on Windows, macOS, and Linux platforms.
Critical Impact
Attackers can deliver malicious files that bypass Chrome's Safe Browsing protection layer, increasing the likelihood that users execute untrusted content without warning.
Affected Products
- Google Chrome prior to 149.0.7827.53
- Microsoft Windows (Chrome desktop)
- Apple macOS and Linux (Chrome desktop)
Discovery Timeline
- 2026-06-05 - CVE-2026-11266 published to NVD
- 2026-06-08 - Last updated in NVD database
Technical Details for CVE-2026-11266
Vulnerability Analysis
The vulnerability resides in Chrome's Safe Browsing subsystem, which inspects downloaded files and URLs against Google's reputation services. The inappropriate implementation permits a crafted file to evade the lookup or classification logic that normally flags malicious content. Because Safe Browsing is the warning surface for risky downloads, a bypass removes the visible signal that would otherwise deter the user from proceeding.
The attack vector is network-based and requires user interaction. The integrity impact is limited, with no direct effect on confidentiality or availability. EPSS data places exploitation probability at the low end of the distribution, consistent with Google's Low Chromium severity classification.
Root Cause
The root cause is a protection mechanism failure [CWE-693] in the Safe Browsing file-handling path. Specific implementation details are restricted in the Chromium issue tracker entry pending broader patch adoption. The Safe Browsing logic fails to apply the expected verdict against certain malicious file payloads, allowing them to reach the user without the standard download warning.
Attack Vector
An attacker hosts a malicious file on an attacker-controlled site or delivers it through a phishing link. The victim, using an unpatched Chrome build, navigates to the resource and initiates a download. Safe Browsing fails to flag the file, and the user receives no warning prompt before execution. The technique is most useful as a component of malware distribution chains rather than as a standalone exploit.
No public proof-of-concept exploit is available, and the issue is not listed on the CISA Known Exploited Vulnerabilities catalog. Refer to the Google Chrome Stable Update advisory for vendor guidance.
Detection Methods for CVE-2026-11266
Indicators of Compromise
- Chrome download events for executable or script files (.exe, .msi, .dll, .js, .hta, .lnk) that completed without a Safe Browsing warning prompt on Chrome versions below 149.0.7827.53.
- Browser history entries pointing to recently registered domains immediately preceding download events.
- Endpoint process creation chains where chrome.exe is the parent of newly written, unsigned binaries executed from user-writable directories.
Detection Strategies
- Inventory Chrome installations across Windows, macOS, and Linux endpoints and flag any build below 149.0.7827.53 as exposed.
- Correlate web proxy or DNS logs with endpoint download telemetry to identify file deliveries that lacked a Safe Browsing classification.
- Apply behavioral analytics on downloaded file execution patterns to catch post-bypass malicious activity even when the initial warning was suppressed.
Monitoring Recommendations
- Forward Chrome browser telemetry and endpoint download events to a centralized logging platform for retroactive hunting.
- Alert on first-seen executable hashes downloaded from low-reputation domains during the exposure window.
- Track Chrome update compliance through enterprise management tooling to confirm rollout of the fixed build.
How to Mitigate CVE-2026-11266
Immediate Actions Required
- Update Google Chrome to version 149.0.7827.53 or later on all Windows, macOS, and Linux endpoints.
- Restart Chrome after the update to ensure the patched Safe Browsing component is loaded.
- Validate enterprise deployment tooling (Google Update, MDM, package managers) is delivering the fixed build to all users.
Patch Information
Google addressed the issue in the Chrome Stable channel release 149.0.7827.53. Details are published in the Chrome Releases blog. Tracking metadata is maintained in the Chromium issue tracker.
Workarounds
- Enable Chrome Enhanced Safe Browsing for users who cannot update immediately, raising the bar for malicious file delivery.
- Restrict execution of newly downloaded binaries via application control or AppLocker policies until patching completes.
- Block known malicious download sources at the web proxy and DNS layers to reduce exposure during the patch rollout window.
# Verify Chrome version on Linux/macOS endpoints
google-chrome --version
# Expected: Google Chrome 149.0.7827.53 or later
# Windows: query installed Chrome version from the registry
reg query "HKLM\Software\Google\Update\Clients\{8A69D345-D564-463C-AFF1-A69D9E530F96}" /v pv
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
