--- title: Is RCE Really Just Low Severity? | daily.dev description: A security researcher discovered a command injection vulnerability in the {fmt} C++ library's `fmt::say` helper, which passes formatted strings directly to... canonical: https://daily.dev/posts/is-rce-really-just-low-severity--op9eitarn twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Is RCE Really Just Low Severity? | daily.dev og:description: A security researcher discovered a command injection vulnerability in the {fmt} C++ library's `fmt::say` helper, which passes formatted strings directly to... og:url: https://daily.dev/posts/is-rce-really-just-low-severity--op9eitarn og:image: https://api.daily.dev/og/posts/Op9eiTaRN.png og:image:alt: Is RCE Really Just Low Severity? og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Is RCE Really Just Low Severity? **[0xkato](https://daily.dev/sources/0xkato)** · 8 min read · 0 upvotes · 0 comments ## Summary A security researcher discovered a command injection vulnerability in the {fmt} C++ library's `fmt::say` helper, which passes formatted strings directly to `std::system`. The post walks through the finding, explains why the researcher initially rated it critical (CVSS 9.8) while the maintainers rated it Low (CVSS ~3.3), and uses the case to illustrate how impact and exposure are separate dimensions of severity. The helper was macOS-only, lived in an optional header, and was removed in the fix. The author argues that library-level and application-level severity can legitimately differ, and raises concern that low library-level scores may cause real application-level risks to be overlooked. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Where Severity Scores Go Wrong: “Just Add Prototype Pollution”](https://daily.dev/posts/where-severity-scores-go-wrong-just-add-prototype-pollution--e2stwdhw0) · JFrog · 0 upvotes · 0 comments - [RCE As a Feature](https://daily.dev/posts/rce-as-a-feature-xeeuukhv1) · The Daily WTF · 0 upvotes · 0 comments - [The CVE spike across major software companies is a remediation problem](https://daily.dev/posts/the-cve-spike-across-major-software-companies-is-a-remediation-problem-eirfbzfqc) · Aikido Security · 0 upvotes · 0 comments - [Langflow RCE under active attack months after a patch was shipped](https://daily.dev/posts/langflow-rce-under-active-attack-months-after-a-patch-was-shipped-jzjannqnb) · CSO Online · 0 upvotes · 0 comments --- Tags: [#security](https://daily.dev/tags/security), [#golang](https://daily.dev/tags/golang) [View this post on daily.dev](https://daily.dev/posts/is-rce-really-just-low-severity--op9eitarn) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Is RCE Really Just Low Severity?","url":"https://daily.dev/posts/is-rce-really-just-low-severity--op9eitarn","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/is-rce-really-just-low-severity--op9eitarn"},"datePublished":"2026-08-02T07:06:56.263Z","dateModified":"2026-08-02T07:20:23.144Z","description":"A security researcher discovered a command injection vulnerability in the {fmt} C++ library's `fmt::say` helper, which passes formatted strings directly to...","image":"https://media.daily.dev/image/upload/s--qPvKM23u--/f_auto/v1722860399/public/Placeholder%2009","thumbnailUrl":"https://media.daily.dev/image/upload/s--qPvKM23u--/f_auto/v1722860399/public/Placeholder%2009","isAccessibleForFree":true,"articleSection":"0xkato","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"0xkato","logo":"https://media.daily.dev/image/upload/s--4y20wV9B--/f_auto,q_auto/v1785654409/logos/0xkato","url":"https://daily.dev/sources/0xkato"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/is-rce-really-just-low-severity--op9eitarn","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"security,golang","timeRequired":"PT8M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"0xkato","item":"https://daily.dev/sources/0xkato"},{"@type":"ListItem","position":3,"name":"Is RCE Really Just Low Severity?"}]} ```