CVE intelligence and bounded remediation
CVE-2026-49136 — Banana Slides security vulnerability
Banana Slides through 0.4.0, patched in commit e8bc490, contains a path traversal vulnerability in the generate_image() function within the AI service backend that allows unauthenticated attackers to read arbitrary image-format files outside the intended uploads directory by exploiting an incomplete path prefix check using os.path.startswith() without a trailing separator. Attackers can supply crafted markdown image references in user-controlled page descriptions that resolve to sibling directories whose names share the uploads folder prefix, bypassing the directory confinement check and causing the application to read files from unintended locations via PIL Image.open().
- Severity
- High
- CVSS
- 8.7 (4.0)
- Published
- 2026-06-01
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-22
Affected products
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Matched remediation archetype
Path traversal, unsafe upload, and file handling
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Check exposure
- Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
- Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
- Review canonicalization and containment checks across supported operating systems and storage backends.
Remediate safely
- Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
- Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
- Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.
Authoritative sources
Complete CVE record and remediation plan
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