U.S. CISA adds Google Brotli and Adobe Commerce and Magento flaws to its Known Exploited Vulnerabilities catalog

U.S. CISA adds Google Brotli and Adobe Commerce and Magento flaws to its Known Exploited Vulnerabilities catalog

Pierluigi Paganini
October 28, 2026

U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds Google Brotli and Adobe Commerce and Magento flaws to its Known Exploited Vulnerabilities catalog.

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added Google Brotli and Adobe Commerce and Magento vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog:

Below are the flaws added to the catalog:

• CVE-2026-111497 (CVSS score: 9.2) – An unchecked return value vulnerability in Google Brotli that could allow a remote, unauthenticated attacker to corrupt decoder memory, expose sensitive information, cause a denial-of-service, or potentially execute arbitrary code by sending a specially crafted Brotli-compressed stream.
• CVE-2026-48356 (CVSS score: 9.3) – An unrestricted file upload vulnerability in Adobe Commerce and Magento that could allow an attacker to execute arbitrary code with the privileges of the current user, potentially gaining elevated access or taking control of the victim’s account or session.

Brotli is a data-compression algorithm developed by Google.It reduces the size of web content, such as HTML, CSS, JavaScript, and other text-based resources. Security researchers have observed exploitation attempts targeting CVE-2026-111497 (aka Node2Shell), a critical flaw in Google’s Brotli library. Previdian recorded one attempt by October 27, while ELLIO researchers recently detected traffic carrying a public exploit that could execute code on vulnerable systems. The activity may indicate attempts to exploit the flaw on a larger scale, but its scope remains unclear. An attacker can trigger the vulnerability to cause crashes, expose sensitive memory or remote code execution when applications decompress attacker-controlled Brotli data. Because Brotli is widely used, multiple projects and vendors have released security updates, including Node.js, PHP, Bun, and Microsoft .NET. Cybersecurity firm Wiz warned that 91% of cloud environments contain resources vulnerable to the flaw, while 82% have publicly exposed Node.js instances.

The second flaw added to the catalog is an unrestricted file upload vulnerability tracked as CVE-2026-48356, dubbed PolyShell. Recently WordPress security firm Sansec warned of attacks exploiting CVE-2026-48356 to infect at least 953 of online stores. The attackers reportedly used a Magento CMS block to insert a malicious loader capable of retrieving and executing a payload hosted under their control.

So far, researchers have not recovered the subsequent payload, leaving the campaign’s ultimate objectives unclear. The activity is believed to have been underway since at least July 2025 and remains ongoing.

According to Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities, FCEB agencies have to address the identified vulnerabilities by the due date to protect their networks against attacks exploiting the flaws in the catalog.

Experts also recommend that private organizations review the Catalog and address the vulnerabilities in their infrastructure.

CISA orders federal agencies to fix the flaws by October 29, 2026.

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Pierluigi Paganini

(SecurityAffairs – hacking, CISA)

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AndyC

Andy Curtis is an award-winning security consultant, researcher and public speaker. He has been working in the computer security industry since the early 1990s, having been employed by state and federal government, leading healthcare and banking providers across three continents. He has given talks about computer security for some of the world’s largest companies, worked with law enforcement agencies on investigations into hacking groups, and is a regular voice on TV and radio explaining IT security threats.

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