VulncastBriefing archive

Daily Brief - 2026-08-06

· 5 vulnerabilities · 7 min listen

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CVE-2026-17556

GitHub Enterprise Server

A path traversal vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to delete arbitrary files and directories on the instance, including the entire user storage directory containing Git LFS objects, release assets, attachments, and avatars. The X-GitHub-Request-Id request header was used without sanitization as a filesystem path segment for the upload buffer directory, so a traversal value pointed the buffer at an arbitrary path and the deferred cleanup routine recursively removed the traversed target. Exploitation required only network reachability to the instance and no authentication, and it worked even when private mode was enabled. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.21.4, 3.20.6, 3.19.10, 3.18.13 and 3.17.19. This vulnerability was reported via the GitHub Bug Bounty program.

  • Path Traversal
  • Arbitrary File Deletion
  • version control
  • web application

CVE-2026-20304

critical · CVSS 9.9 · Cisco Catalyst SD-WAN

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Catalyst SD-WAN engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20304 are related to improper access control issues that are grouped under the Common Weakness Enumeration (CWE) CWE-284.

  • Improper Access Control
  • sd-wan

CVE-2026-70426

critical · CVSS 9 · Jenkins Remoting

In Remoting 3384.v60d89463d9e0 and earlier, except 3355.3357.v931d3c992987, included in Jenkins 2.575 and earlier, LTS 2.568.1 and earlier, the JEP-200 class filter is not applied to classes resolved via a fallback path in the Remoting deserialization implementation, allowing agent processes, code running on agents, and attackers with Agent/Connect permission to bypass the JEP-200 deserialization filter for classes on the Jenkins core classpath.

  • Deserialization Vulnerability
  • Remote Code Execution
  • agent communication

CVE-2026-8400

high · CVSS 8.1 · IBM WebSphere Application Server

IBM WebSphere Application Server 8.5, and 9.0 and IBM WebSphere Application Server - Liberty Continuous delivery has a flaw in the ORB component in IBM SDK, Java Technology Edition, may allow a malicious IIOP server to induce loading and instantation of arbitrary classes.

  • Remote Code Execution
  • java
  • application server

CVE-2026-9193

critical · CVSS 9.9

An improper privilege management vulnerability in the Hadoop integration of Progress MarkLogic Server before 11.3.6 and 12.0.3 allows an authenticated user with a low-privileged Hadoop role to escalate privileges and execute privileged operations against the Security database.