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OpenAdvisories
Low · 3.1 CVE-2026-39396 BIT-openbao-2026-39396EUVD-2026-24031GHSA-r65v-xgwc-g56jGO-2026-5609

OpenBao has Decompression Bomb via Unbounded Copy in OCI Plugin Extraction (DoS)

Published Apr 21, 2026 · Updated Apr 21, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
openbao openbao < 2.5.3 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Tumbleweed openbao 2.5.3-1.1 openSUSE-SU-2026:10594-1
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1
ReleasePackageFixed inAdvisory
Alpine v3.24 openbao 2.5.4-r0 —
Alpine v3.23 openbao 2.5.4-r0 —

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling openbao +1 2.5.3-r0 —

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/openbao/openbao < 0.0.0-20260420180337-2b2a901aa9f7 0.0.0-20260420180337-2b2a901aa9f7 GHSA-r65v-xgwc-g56j

Advisories 3

References