Description

Release attachment extension allowlist bypass via web release edit form (variant of CVE-2025-68939)

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.5",
  "pubDate": "2026-08-13T17:17:26.833Z",
  "pubdate": "2026-08-13T17:17:26.833Z",
  "executiveSummary": "This vulnerability involves a release attachment extension allowlist bypass via the web release edit form, functioning as a variant of CVE-2025-68939.\nThe security flaw allows unauthorized or restricted file types to be uploaded as release attachments by circumventing the client-side or server-side validation mechanisms enforced by the web release edit form.\nThe primary impact includes the potential upload of malicious executable files, scripts, or other dangerous formats disguised as permitted file types, which could subsequently lead to remote code execution, stored cross-site scripting, or further compromise depending on how release attachments are processed and served to end users.\nThe affected system components involve the web-based interface utilized for editing and managing software releases and their associated attachments.\nRisk implications are significant, as successful exploitation undermines file type restrictions and integrity controls designed to prevent the storage of unsafe payloads within release repositories.\nAttacker capabilities require access to the web release edit form interface, allowing them to manipulate the file upload parameters or submit requests that bypass the intended allowlist validation checks.\nExploitation requirements depend on interacting with the vulnerable web release edit form and identifying the specific validation weakness that permits the restricted file extension to be successfully processed and stored by the application.",
  "technicalDetails": "The root cause of this vulnerability stems from insufficient or improperly implemented validation checks within the web release edit form handling file attachment uploads, allowing an attacker to bypass the release attachment extension allowlist.\nAs a variant of CVE-2025-68939, the flaw indicates that previous remediation efforts or standard validation controls failed to adequately secure all entry points or normalization steps associated with the file upload functionality.\nThe vulnerable component resides in the web application logic responsible for processing release edits and validating uploaded file extensions against an enforced security allowlist.\nExploitation occurs when an attacker crafts a malicious HTTP request via the web release edit form, substituting a restricted or dangerous file extension with an allowed format, or manipulating parameters to evade strict extension parsing routines.\nThe attack flow typically proceeds as follows: First, the attacker navigates to the web release edit form interface associated with a target release. Second, the attacker selects a file with a prohibited extension (such as an executable or script format) intended for upload. Third, during the submission process, the attacker leverages the bypass mechanism—such as MIME-type spoofing, null-byte injection, double extensions, or direct parameter manipulation—to trick the validation routine into evaluating the file as compliant. Fourth, the application accepts the file, bypasses the allowlist enforcement, and successfully stores the attachment within the release repository.\nNetwork exposure involves the web interface accessible to users authorized to interact with release management features.\nAuthentication and privilege requirements depend on the specific access control configuration of the web release edit form, potentially requiring authenticated access with permissions to edit or create software releases.\nPayload behavior following successful exploitation includes the persistence of unauthorized file types within the release storage infrastructure, which can then be downloaded by consumers of the release or potentially executed if the application or server misinterprets the file context.\nPost-exploitation impact may encompass arbitrary code execution on client machines downloading the malicious release asset, malware distribution through official channels, or stored cross-site scripting if HTML or script-based attachments are rendered improperly by the web application."
}