{"id":"CVE-2026-69522","kind":"vulnerability","aliases":["CVE-2026-69522","GHSA-2j8r-3c22-8565"],"related":[],"title":"Microsoft Security Advisory CVE-2026-69522 – .NET and Visual Studio Remote Code Execution Vulnerability","description":"# Microsoft Security Advisory CVE-2026-69522 – .NET and Visual Studio Remote Code Execution Vulnerability\n\n## Executive summary\n\nMicrosoft is releasing this security advisory to provide information about a vulnerability in Microsoft.DiaSymReader.Native. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.\n\nAn out of bounds write can occur when processing PDB files.\n\n## Announcement\n\nAnnouncement for this issue can be found at https://github.com/dotnet/announcements/issues/439\n\n## CVSS Details\n\n- **Version:** 3.1\n- **Severity:** High\n- **Score:** 8.8\n- **Vector:** `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`\n- **Weakness:** CWE-122 (Heap-based Buffer Overflow)\n\n## Affected Platforms\n\n- **Platforms:** Windows\n- **Architectures:** All\n\n## <a name=\"affected-packages\"></a>Affected Packages\nThe vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below\n\nSupported .NET Framework versions listed in the [Microsoft Security Update Guide](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69522) are also affected. Install the September 2026 .NET Framework security update applicable to a project's Windows version.\n\n### <a name=\".NET 11 RC1\"></a>.NET 11 RC1\nPackage name | Affected version | Patched version\n------------ | ---------------- | -------------------------\n[Microsoft.DiaSymReader.Native](https://www.nuget.org/packages/Microsoft.DiaSymReader.Native) | >= 17.10.0-beta1.24272.1, <= 18.9.0-beta1.26405.1 | 18.9.0-beta1.26405.2\n\n### <a name=\".NET 10\"></a>.NET 10\nPackage name | Affected version | Patched version\n------------ | ---------------- | -------------------------\n[Microsoft.DiaSymReader.Native](https://www.nuget.org/packages/Microsoft.DiaSymReader.Native) | >= 17.12.0-beta1.24603.5, <= 18.9.0-beta1.26405.1 | 18.9.0-beta1.26405.2\n\n### <a name=\".NET 9\"></a>.NET 9\nPackage name | Affected version | Patched version\n------------ | ---------------- | -------------------------\n[Microsoft.DiaSymReader.Native](https://www.nuget.org/packages/Microsoft.DiaSymReader.Native) | >= 17.12.0-beta1.24603.5, <= 18.9.0-beta1.26405.1 | 18.9.0-beta1.26405.2\n\n### <a name=\".NET 8\"></a>.NET 8\nPackage name | Affected version | Patched version\n------------ | ---------------- | -------------------------\n[Microsoft.DiaSymReader.Native](https://www.nuget.org/packages/Microsoft.DiaSymReader.Native) | >= 17.12.0-beta1.24603.5, <= 18.9.0-beta1.26405.1 | 18.9.0-beta1.26405.2\n\n## Advisory FAQ\n\n### <a name=\"how-affected\"></a>How do I know if I am affected?\n\nIf using a package listed in [affected packages](#affected-packages), a project is exposed to the vulnerability.\n\n### <a name=\"how-fix\"></a>How do I fix the issue?\n\n1. To fix the issue please install the latest version of .NET or Visual Studio. .NET Framework users must install the September 2026 security update applicable to their Windows version.\n2. If a developer's application references Microsoft.DiaSymReader.Native, update the package reference to version 18.9.0-beta1.26405.2 or later.\n\nOnce users have installed the updated runtime, SDK, Visual Studio, or package, they should restart their apps for the update to take effect.\n\n## Other Information\n\n### Reporting Security Issues\n\nIf users have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the [MSRC Researcher Portal](https://msrc.microsoft.com/report/vulnerability/new). Further information can be found in the MSRC [Report an Issue FAQ](https://www.microsoft.com/msrc/faqs-report-an-issue).\n\nSecurity reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.\n\n### Support\n\nUsers can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. Users can ask questions in the linked discussion issue.\n\n### Disclaimer\n\nThe information provided in this advisory is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.\n\n### External Links\n\n[CVE-2026-69522](https://www.cve.org/CVERecord?id=CVE-2026-69522)\n\n### Acknowledgements\n\n41ae55e9310ff27fa6f26af4727e5590\n\n### Revisions\n\nV1.0 (09/08/2026): Advisory published.","summary":"Microsoft.DiaSymReader.Native, a NuGet package used by .NET and Visual Studio to read PDB debug files, has a heap buffer overflow when processing PDB files. An attacker who gets a crafted PDB file processed on a Windows machine can run code there.","severity":"high","cvss":8.8,"epss":0.00837,"exploited":false,"exploited_at":null,"products":[{"name":"Microsoft.DiaSymReader.Native","fixed":["18.9.0-beta1.26405.2"],"affected":">= 17.10.0-beta1.24272.1, <= 18.9.0-beta1.26405.1","ecosystem":"nuget"}],"ecosystems":["nuget"],"tags":["cwe-122","dotnet","nuget","package","visual-studio","windows"],"not_affected_if":["non-windows","package-not-referenced","patched-version"],"how_to_check":"- List package references in each project for `Microsoft.DiaSymReader.Native` and check whether the resolved version is between `17.10.0-beta1.24272.1` and `18.9.0-beta1.26405.1` (.NET 10, 9 and 8 ranges differ, see the advisory)\n- Check the .NET or Visual Studio install and the .NET Framework security updates on Windows machines that build or debug projects","fix":null,"status":"open","published_at":"2026-09-08T18:19:19+00:00","first_seen_at":"2026-11-04T04:12:13+00:00","triaged_at":"2026-11-04T04:14:22+00:00","updated_at":"2026-11-04T04:16:16+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-11-04T04:14:22Z","model":"claude-haiku-5-5","output":{"fix":"- Microsoft.DiaSymReader.Native: update the package reference to `18.9.0-beta1.26405.2` or later\n- .NET and Visual Studio: install the latest version; .NET Framework users install the September 2026 security update for their Windows version","reach":"unknown","title":".NET: PDB file parsing out-of-bounds write allows remote code execution","impact":"high","summary":"Microsoft.DiaSymReader.Native, a NuGet package used by .NET and Visual Studio to read PDB debug files, has a heap buffer overflow when processing PDB files. An attacker who gets a crafted PDB file processed on a Windows machine can run code there.","audience":"developers","category":"package","nicknames":[],"who_cares":["dotnet","nuget","visual-studio","windows"],"confidence":0.7,"fix_status":"available","needs_auth":"no","worst_case":"code runs on the developer or build machine","analyst_note":"","how_to_check":"- List package references in each project for `Microsoft.DiaSymReader.Native` and check whether the resolved version is between `17.10.0-beta1.24272.1` and `18.9.0-beta1.26405.1` (.NET 10, 9 and 8 ranges differ, see the advisory)\n- Check the .NET or Visual Studio install and the .NET Framework security updates on Windows machines that build or debug projects","plain_action":"","needs_analyst":false,"not_affected_if":["non-windows","package-not-referenced","patched-version"],"who_is_affected":"Any .NET project on Windows that references Microsoft.DiaSymReader.Native within the affected ranges, and machines running the affected .NET or Visual Studio builds, are exposed. The advisory says the flaw is triggered when PDB files are processed, so the risk depends on whether a project or tool reads PDB files from untrusted sources; the advisory gives no further detail.","user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.00096,"input_tokens":6173,"output_tokens":686,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-122':28B,169C '-2026':5A,16A,24A,80C '-69522':6A,17A,25A,81C '/av':158C '/corebounty.':489C '/dotnet/announcements/issues/439':146C '/dotnet/runtime.':513C '/msrc/faqs-report-an-issue).':461C '/packages/microsoft.diasymreader.native)':244C,262C,280C,298C '/report/vulnerability/new).':446C '/update-guide/vulnerability/cve-2026-69522)':213C '1':339C '10':252C '11':233C '17.10.0':245C '17.12.0':263C,281C,299C '18.9.0':247C,249C,265C,267C,283C,285C,301C,303C,383C '2':369C '2026':220C,361C '2j8r':20A '3.1':150C,157C '3c22':21A '8':288C '8.8':154C '8565':22A '9':270C 'advisori':3A,78C,97C,107C,305C 'affect':175C,181C,185C,195C,216C,237C,255C,273C,291C,314C,321C,324C 'affected-packag':323C 'aka.ms':488C 'aka.ms/corebounty.':487C 'also':108C,215C 'announc':135C,136C,515C 'app':403C 'applic':119C,225C,364C,374C 'architectur':179C 'ask':493C 'attack':61B 'base':172C 'beta1.24272.1':246C 'beta1.24603.5':264C,282C,300C 'beta1.26405.1':248C,266C,284C,302C 'beta1.26405.2':250C,268C,286C,304C,384C 'bound':127C 'bounti':473C,479C 'buffer':54B,173C 'center':437C 'code':12A,75B,87C 'condit':484C 'craft':65B 'cve':4A,15A,23A,79C 'cvss':147C,156C 'cwe':27B,168C 'debug':49B 'detail':148C,474C 'develop':113C,372C 'dotnet':29B 'effect':409C 'execut':13A,88C,90C 'expos':329C 'faq':306C,458C 'file':50B,59B,67B,134C 'fix':336C,341C 'found':142C,418C,451C 'framework':202C,222C,355C 'get':63B 'ghsa':19A 'ghsa-2j8r-3c22':18A 'github':499C,503C 'github.com':145C,512C 'github.com/dotnet/announcements/issues/439':144C 'github.com/dotnet/runtime.':511C 'guid':210C 'guidanc':110C 'h':166C 'h/a':165C 'h/i':164C 'heap':53B,171C 'heap-bas':170C 'high':152C 'includ':481C 'inform':100C,411C,448C 'instal':217C,345C,358C,390C 'issu':139C,338C,343C,414C,422C,457C,497C 'know':310C 'l/pr':160C 'later':386C 'latest':347C 'list':198C,204C,319C 'locat':509C 'machin':72B 'made':464C 'main':506C 'may':467C 'microsoft':1A,76C,92C,187C,207C,434C,471C,477C 'microsoft.diasymreader.native':26A,36B,105C,241C,259C,277C,295C,376C 'msrc':438C,441C,454C,466C 'msrc.microsoft.com':212C,445C 'msrc.microsoft.com/report/vulnerability/new).':444C 'msrc.microsoft.com/update-guide/vulnerability/cve-2026-69522)':211C 'must':357C 'n/ac':159C 'n/ui':161C 'name':236C,254C,272C,290C 'net':7A,42B,82C,188C,201C,221C,232C,251C,269C,287C,350C,354C,428C,472C,478C,502C 'nuget':30B,38B 'occur':130C 'organ':504C 'overflow':55B,174C 'packag':31B,39B,182C,196C,235C,253C,271C,289C,318C,322C,325C,379C,398C 'patch':239C,257C,275C,293C 'pdb':48B,58B,66B,133C 'platform':176C,177C 'pleas':344C,429C 'portal':443C 'potenti':420C 'process':57B,68B,132C 'program':480C 'project':189C,228C,327C 'provid':99C,109C 'qualifi':468C 'question':494C 'r/s':162C 'rc1':234C 'read':47B 'refer':375C,380C 'releas':94C 'remot':11A,86C 'remov':121C 'repo':507C 'report':412C,430C,455C,463C 'research':442C 'respons':436C 'restart':401C 'run':74B 'runtim':393C 'score':153C 'sdk':394C 'secur':2A,77C,96C,208C,223C,362C,413C,421C,435C,462C 'septemb':219C,360C 'sever':151C 'studio':10A,34B,45B,85C,353C,396C 'summari':91C 'support':200C,425C,490C 'take':408C 'term':482C 'u/c':163C 'updat':117C,209C,224C,363C,377C,392C,406C 'use':40B,192C,316C 'user':356C,388C,416C,491C 'vector':155C 'version':149C,197C,203C,231C,238C,240C,256C,258C,274C,276C,292C,294C,348C,368C,382C,426C 'via':439C 'visual':9A,33B,44B,84C,352C,395C 'visual-studio':32B 'vulner':14A,89C,103C,123C,184C,332C 'weak':167C 'window':35B,71B,178C,230C,367C 'write':128C 'www.microsoft.com':460C 'www.microsoft.com/msrc/faqs-report-an-issue).':459C 'www.nuget.org':243C,261C,279C,297C 'www.nuget.org/packages/microsoft.diasymreader.native)':242C,260C,278C,296C","nicknames":[],"mitigations":[],"who_affected":"Any .NET project on Windows that references Microsoft.DiaSymReader.Native within the affected ranges, and machines running the affected .NET or Visual Studio builds, are exposed. The advisory says the flaw is triggered when PDB files are processed, so the risk depends on whether a project or tool reads PDB files from untrusted sources; the advisory gives no further detail.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":["microsoftdiasymreadernative"],"ptokens":["diasymreader","microsoft","native"],"labels":["cwe122","dotnet","high","nuget","package","visualstudio","windows"],"campaign_type":null,"first_public_at":"2026-09-08T18:19:19+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cvss_by":"GitHub","poc_count":0,"sources":[{"source":"ghsa","external_id":"GHSA-2j8r-3c22-8565","url":"https://github.com/advisories/GHSA-2j8r-3c22-8565","severity":"high","published_at":"2026-09-09T16:04:04+00:00","modified_at":"2026-11-04T04:09:29+00:00","first_seen_at":"2026-11-04T04:12:13+00:00","fetched_at":"2026-11-04T04:48:11+00:00","note":null},{"source":"nvd","external_id":"CVE-2026-69522","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-69522","severity":null,"published_at":"2026-09-08T18:19:19+00:00","modified_at":"2026-10-30T22:17:33+00:00","first_seen_at":"2026-11-04T04:16:16+00:00","fetched_at":"2026-11-04T04:16:16+00:00","note":null}],"documents":[{"id":63877,"url":"https://api.github.com/repos/dotnet/runtime/security-advisories/GHSA-2j8r-3c22-8565","title":"Maintainer's advisory: api.github.com","kind":"vendor","source":"ghsa","publisher":"vendor","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Maintainer's advisory: api.github.com"},{"id":63878,"url":"https://github.com/dotnet/runtime/security/advisories/GHSA-2j8r-3c22-8565","title":"Maintainer's advisory: github.com","kind":"vendor","source":"ghsa","publisher":"vendor","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Maintainer's advisory: github.com"}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}