{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/firefox-esr/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Firefox","Firefox ESR"],"_cs_severities":["medium"],"_cs_tags":["firefox","vulnerability","mozilla"],"_cs_type":"advisory","_cs_vendors":["Mozilla"],"content_html":"\u003cp\u003eOn April 28, 2026, Mozilla published a security advisory (AV26-401) addressing multiple vulnerabilities in Firefox and Firefox ESR. The affected products include Firefox versions prior to 150.0.1, Firefox ESR versions prior to 140.10.1, and Firefox ESR versions prior to 115.35.1. Successful exploitation of these vulnerabilities could lead to arbitrary code execution, information disclosure, or denial-of-service. The Cyber Centre encourages users and administrators to review the provided web links and apply the necessary updates to mitigate the risks associated with these vulnerabilities. These vulnerabilities could be exploited by attackers to compromise user systems.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker crafts a malicious webpage or injects malicious code into a trusted website.\u003c/li\u003e\n\u003cli\u003eA user visits the malicious website or a compromised trusted website using a vulnerable version of Firefox.\u003c/li\u003e\n\u003cli\u003eThe browser parses the malicious HTML/JavaScript code.\u003c/li\u003e\n\u003cli\u003eOne of the vulnerabilities (memory corruption, use-after-free, etc.) is triggered during the parsing or rendering process.\u003c/li\u003e\n\u003cli\u003eThe attacker gains control of the browser process.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages the gained control to execute arbitrary code on the user\u0026rsquo;s system.\u003c/li\u003e\n\u003cli\u003eThe attacker installs malware, such as a keylogger or remote access trojan (RAT).\u003c/li\u003e\n\u003cli\u003eThe attacker performs malicious activities, such as stealing sensitive data or establishing a command and control channel.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of these vulnerabilities could lead to arbitrary code execution, potentially allowing an attacker to gain control of the affected system. This can lead to data theft, malware installation, and further compromise of the network. The scope of impact depends on the privileges of the user running the vulnerable Firefox version. Since Firefox is a widely used browser, a large number of users are potentially at risk if they do not apply the necessary updates.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade Firefox to version 150.0.1 or later to patch the vulnerabilities (refer to \u003ca href=\"https://www.mozilla.org/en-US/security/advisories/mfsa2026-35/\"\u003eMozilla Foundation Security Advisory 2026-35\u003c/a\u003e).\u003c/li\u003e\n\u003cli\u003eUpgrade Firefox ESR to version 140.10.1 or later to patch the vulnerabilities (refer to \u003ca href=\"https://www.mozilla.org/en-US/security/advisories/mfsa2026-36/\"\u003eMozilla Foundation Security Advisory 2026-36\u003c/a\u003e).\u003c/li\u003e\n\u003cli\u003eUpgrade Firefox ESR to version 115.35.1 or later to patch the vulnerabilities (refer to \u003ca href=\"https://www.mozilla.org/en-US/security/advisories/mfsa2026-37/\"\u003eMozilla Foundation Security Advisory 2026-37\u003c/a\u003e).\u003c/li\u003e\n\u003cli\u003eDeploy the \u0026ldquo;Detect Firefox Process Launching Suspicious Child Process\u0026rdquo; Sigma rule to identify potential exploitation attempts.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-29T12:00:00Z","date_published":"2026-04-29T12:00:00Z","id":"/briefs/2026-04-mozilla-vulns/","summary":"Mozilla released a security advisory addressing vulnerabilities in Firefox and Firefox ESR versions prior to 150.0.1, 140.10.1, and 115.35.1, potentially leading to arbitrary code execution or information disclosure.","title":"Mozilla Firefox Multiple Vulnerabilities","url":"https://feed.craftedsignal.io/briefs/2026-04-mozilla-vulns/"}],"language":"en","title":"CraftedSignal Threat Feed — Firefox ESR","version":"https://jsonfeed.org/version/1.1"}