{"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/commonmark-1.5.0-2.09.0/feed.json","home_page_url":"https://feed.craftedsignal.io/","icon":"https://feed.craftedsignal.io/apple-touch-icon.png","items":[{"_cs_actors":[],"_cs_cpes":["cpe:2.3:a:commonmark:commonmark:*:*:*:*:*:*:*:*"],"_cs_cves":[{"cvss":7.5,"id":"CVE-2026-86428"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["commonmark (1.5.0-2.09.0)"],"_cs_severities":["low"],"_cs_tags":["denial-of-service","vulnerability","web-application"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eCommonMark, a library used for parsing Markdown, contains a vulnerability (CVE-2026-86428) in the AttributesExtension component affecting versions 1.5.0 through 2.09.0. The vulnerability stems from an inefficient algorithm used for merging and filtering attributes when processing user-provided Markdown content. Specifically, an attacker can supply a specially crafted Markdown string containing a high volume of distinct attribute names. When the library attempts to process these attributes, the underlying logic performs a quadratic-time operation that consumes excessive CPU resources. This resource exhaustion leads to a denial-of-service state, where the application becomes unresponsive to legitimate requests. Given that Markdown parsing is frequently utilized in web applications to render user-generated content, this vulnerability poses a significant risk to the availability of systems that rely on this library.\u003c/p\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this vulnerability results in CPU exhaustion, which can cause significant latency or a complete service outage for the hosting application. This denial-of-service vector is particularly dangerous for platforms that allow unauthenticated users to submit or render arbitrary Markdown content, as it allows attackers to disrupt service with relatively small, high-impact payloads.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cp\u003ePrioritize the immediate remediation of affected environments to prevent service disruption caused by resource exhaustion.\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade the CommonMark library to version 2.10.0 or later immediately to resolve the algorithmic complexity flaw associated with CVE-2026-86428.\u003c/li\u003e\n\u003cli\u003eImplement request timeout mechanisms and CPU resource limits on application components that parse Markdown to mitigate the impact of potential DoS attacks.\u003c/li\u003e\n\u003cli\u003eMonitor application-level logs for spikes in CPU utilization correlated with Markdown rendering tasks to identify attempted exploitation.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-09-07T13:36:58Z","date_published":"2026-09-07T13:36:58Z","id":"https://feed.craftedsignal.io/briefs/2026-09-commonmark-dos/","summary":"CommonMark versions 1.5.0 through 2.09.0 are susceptible to a CPU-exhaustion denial-of-service attack due to inefficient attribute processing within the AttributesExtension.","title":"Denial of Service Vulnerability in CommonMark AttributesExtension","url":"https://feed.craftedsignal.io/briefs/2026-09-commonmark-dos/"}],"language":"en","title":"CraftedSignal Threat Feed - Commonmark (1.5.0-2.09.0)","version":"https://jsonfeed.org/version/1.1"}