CVE-2026-87505VulnerabilityPublished 09/09/2026Updated 09/10/2026

CVE-2026-87505: Incorrect authorization in Google Chrome

Affects Google ChromeSource GCVE Database

ghsa-v3g2-fh7f-m49v

Not known to be exploited · CVSS 8.1 High · fixed in 153.0.8010.36 : patch Google Chrome soon.

Data as of 10/25/2026, 04:40:14 UTC

CVSS 3.1 base score

8.1High

How severe the flaw is on the 0–10 CVSS scale.

Exploitation: Not in CISA KEV, no exploitation reported
EPSS: 0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 153.0.8010.36

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

What to do

Affected software

Product	Affected	Fixed in
Googlegoogle/chrome`pkg:deb/google/chrome`Other threats	Affected <153.0.8010.36	Fixed in 153.0.8010.36

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in Google Chrome version 153.0.8010.36. Users and administrators should update to this version or later to remediate the vulnerability. There is no indication of known exploits in the wild at this time.

Description

CVE-2026-87505 is a vulnerability in Google Chrome's FileSystem authorization prior to version 153.0.8010.36. It allows a remote attacker who has compromised the renderer process to bypass site isolation by using a specially crafted PDF file. The vulnerability has a high severity rating with a CVSS score of 8.1.

Impact

Successful exploitation can lead to a bypass of site isolation, which is a security feature designed to separate different web origins and prevent data leakage between them. This could result in unauthorized access to sensitive information across sites within the browser context. The CVSS score of 8.1 indicates a high impact on confidentiality and integrity, with no impact on availability.

Summary

This vulnerability involves incorrect authorization in the FileSystem component of Google Chrome versions before 153.0.8010.36. An attacker who has already compromised the renderer process can exploit this flaw by crafting a malicious PDF file to bypass site isolation protections, potentially leading to unauthorized access to data across different sites within the browser.

Weaknesses

CWE-863Incorrect Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #17OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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