{"answers":{"affected":"2 open source packages ship an affected version, including deno. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-55517 in the wild and no public exploit code.","fix":"Upgrade deno to 2.7.5 or later.","what":"CVE-2026-55517 is a medium-severity denial of service vulnerability in denoland deno, published on 23 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-55517 and fix it if it is affected.\n\nWhat it is: CVE-2026-55517 is a medium-severity denial of service vulnerability in denoland deno, published on 23 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-55517 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- deno (crates.io): affected all versions; fixed in 2.7.5\n- deno (crates.io): affected all versions; fixed in 2.7.5\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-55517/ (Markdown: https://insights.sbomify.com/CVE-2026-55517/index.md)","id":"CVE-2026-55517","markdown":"https://insights.sbomify.com/CVE-2026-55517/index.md","name":"CVE-2026-55517","record":{"aliases":["GHSA-x2qc-cmh9-f4hf","JLSEC-2026-1167"],"analysis":{"component_type":"developer_tool","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Deno runtime","requires_auth":"none","summary":"A remote server can crash a Deno client application by sending non-ASCII bytes in WebSocket response headers, causing a process panic.","user_interaction":"required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"deno","vendor":"deno"}],"cvss":{"score":4.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L","version":"3.1"},"cwes":[{"id":"CWE-248","name":"Uncaught Exception"}],"description":"Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.5, a Deno program that opens a client WebSocket connection could be crashed by the remote server. While handling the WebSocket handshake response, Deno parsed the Sec-WebSocket-Protocol and Sec-WebSocket-Extensions response headers in a way that assumed their bytes were always printable ASCII. A response header containing non-visible-ASCII bytes (0x80-0xFF) caused a panic that aborted the entire Deno process. This vulnerability is fixed in 2.7.5.","ecosystems":["crates.io"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Deno: Denial of service via non-ASCII bytes in WebSocket response headers","id":"CVE-2026-55517","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"crates.io","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":2,"n_references":1,"next":{"headline":"Avo: Missing Authorization in Avo Association Attach Endpoint Allows Unauthorized Relationship Manipulation and Privilege Escalation","id":"CVE-2026-55518"},"packages":[{"ecosystem":"crates.io","fixed":["2.7.5"],"introduced":["0"],"last_affected":[],"package":"deno","purl":null,"source":"GHSA-x2qc-cmh9-f4hf"},{"ecosystem":"crates.io","fixed":["2.7.5"],"introduced":["0"],"last_affected":[],"package":"deno","purl":"pkg:cargo/deno","source":"GHSA-x2qc-cmh9-f4hf"}],"prev":{"headline":"Snipe-IT: Cross-company asset maintenance re-parenting via API update","id":"CVE-2026-55516"},"products":["deno"],"published":"2026-06-23","related":[{"cvss_score":10,"headline":"Deno improperly handles resizable ArrayBuffer","id":"CVE-2023-28445","kev_date_added":null,"published":"2023-03-23"},{"cvss_score":10,"headline":"Sandbox bypass leading to arbitrary code execution in Deno","id":"CVE-2022-24783","kev_date_added":null,"published":"2022-03-25"},{"cvss_score":9.8,"headline":"Static imports inside dynamically imported modules do not adhere to permission checks","id":"CVE-2021-32619","kev_date_added":null,"published":"2021-05-28"},{"cvss_score":9.2,"headline":"Deno node:crypto doesn't finalize cipher","id":"CVE-2026-22863","kev_date_added":null,"published":"2026-01-15"},{"cvss_score":8.8,"headline":"Deno interactive permission prompt spoofing via improper ANSI stripping","id":"CVE-2024-27936","kev_date_added":null,"published":"2024-03-06"},{"cvss_score":8.8,"headline":"Deno is vulnerable to interactive `run` permission prompt spoofing via improper ANSI neutralization","id":"CVE-2023-28446","kev_date_added":null,"published":"2023-03-24"},{"cvss_score":8.6,"headline":"Deno missing \"--allow-net\" permission check for built-in Node modules","id":"CVE-2023-33966","kev_date_added":null,"published":"2023-05-31"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-06-23","vendors":["denoland"]},"summary":"A remote server can crash a Deno client application by sending non-ASCII bytes in WebSocket response headers, causing a process panic.","url":"https://insights.sbomify.com/CVE-2026-55517/"}