{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","favicon":"https://feed.craftedsignal.io/favicon-32x32.png","feed_url":"https://feed.craftedsignal.io/products/astro--7.2.8/feed.json","home_page_url":"https://feed.craftedsignal.io/","icon":"https://feed.craftedsignal.io/apple-touch-icon.png","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Astro (\u003c 7.2.8)"],"_cs_severities":["critical"],"_cs_tags":[],"_cs_type":"advisory","_cs_vendors":["Astro"],"content_html":"\u003cp\u003eA critical vulnerability exists in the Astro web framework due to the underlying libheif library used by the default Sharp image service. The vulnerability, tracked as GHSA-26w7-cxv4-gfx2, arises from out-of-bounds read and write operations (CWE-125 and CWE-787) during the optimization of AVIF image files. An attacker can achieve remote code execution (RCE) by supplying a specially crafted, malicious AVIF image to an Astro application that is configured to process or optimize user-uploaded or externally sourced imagery. This vulnerability allows for unauthenticated exploitation with no user interaction required. The fix was introduced in Astro 7.2.8, which mandates the use of Sharp 0.35.4. Given the nature of RCE, this poses a significant risk to the integrity and availability of any internet-facing Astro site that supports image transformation.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies an Astro-based web application that utilizes the default Sharp image service for on-the-fly image optimization.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious AVIF image file specifically designed to trigger out-of-bounds memory access (read/write) within the libheif decoding process.\u003c/li\u003e\n\u003cli\u003eThe attacker uploads the malicious image to the target application or forces the application to fetch the malicious file via an image transformation URL.\u003c/li\u003e\n\u003cli\u003eThe Astro application invokes the Sharp service to optimize or resize the provided image.\u003c/li\u003e\n\u003cli\u003eThe underlying libheif library processes the malicious AVIF headers or bitstream.\u003c/li\u003e\n\u003cli\u003eThe out-of-bounds memory corruption triggers a controlled overwrite of memory or flow redirection.\u003c/li\u003e\n\u003cli\u003eThe process executes arbitrary attacker-supplied code or shell commands within the context of the web server process.\u003c/li\u003e\n\u003cli\u003eThe final objective is achieved, resulting in full system compromise or persistence on the affected server.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation allows an unauthenticated attacker to execute arbitrary code on the web server with the privileges of the Astro application process. This can lead to full compromise of the application environment, exfiltration of sensitive configuration data or user information, and service disruption. The CVSS score for this vulnerability is 9.8, indicating maximum severity.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eUpgrade the Astro framework to version 7.2.8 or later immediately, which bundles the patched Sharp 0.35.4 library.\u003c/li\u003e\n\u003cli\u003eImplement strict input validation or file type allowlisting for any user-uploaded content processed by the image service.\u003c/li\u003e\n\u003cli\u003eIf immediate patching is not possible, disable the image transformation service for untrusted or external image sources.\u003c/li\u003e\n\u003cli\u003eInspect web server access logs for anomalous file upload requests or URI-encoded strings indicative of file manipulation prior to the application of the patch.\u003c/li\u003e\n\u003c/ol\u003e\n","date_modified":"2026-09-08T21:48:39Z","date_published":"2026-09-08T21:48:39Z","id":"https://feed.craftedsignal.io/briefs/2026-09-astro-rce/","summary":"A critical vulnerability in the libheif library used by the Astro framework allows unauthenticated remote code execution when processing maliciously crafted AVIF images.","title":"Remote Code Execution in Astro via libheif AVIF Optimization","url":"https://feed.craftedsignal.io/briefs/2026-09-astro-rce/"}],"language":"en","title":"CraftedSignal Threat Feed - Astro (\u003c 7.2.8)","version":"https://jsonfeed.org/version/1.1"}