OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3, `ExtractPluginFromImage()` in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via `io.Copy` with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file. The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace **legit plugin image** with no need to change its signature. Version 2.5.3 contains a patch.
Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 21 Apr 2026 02:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Openbao
Openbao openbao |
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| Vendors & Products |
Openbao
Openbao openbao |
Tue, 21 Apr 2026 01:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3, `ExtractPluginFromImage()` in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via `io.Copy` with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file. The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace **legit plugin image** with no need to change its signature. Version 2.5.3 contains a patch. | |
| Title | OpenBao has Decompression Bomb via Unbounded Copy in OCI Plugin Extraction (DoS) | |
| Weaknesses | CWE-400 CWE-674 CWE-770 |
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| References |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-04-21T00:44:53.943Z
Reserved: 2026-04-06T22:06:40.516Z
Link: CVE-2026-39396
No data.
Status : Received
Published: 2026-04-21T01:16:06.507
Modified: 2026-04-21T01:16:06.507
Link: CVE-2026-39396
No data.
OpenCVE Enrichment
Updated: 2026-04-21T02:30:25Z