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TI-2026-28381 Aliases CVE-2026-39396GHSA-r65v-xgwc-g56j

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

Priority MEDIUM 62CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-400.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00218 12th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed openbao (openbao): 2.5.3github.com/openbao/openbao (Go): 0.0.0-20260420180337-2b2a901aa9f7

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
openbaoopenbaobefore 2.5.32.5.3Patch availableCNA
—github.com/openbao/openbao (Go)before 0.0.0-20260420180337-2b2a901aa9f70.0.0-20260420180337-2b2a901aa9f7Patch availableGHSA-r65v-xgwc-g56j
  • openbao Vendoropenbao Affected before 2.5.3 Fixed in 2.5.3 Patch available CNA
  • github.com/openbao/openbao (Go) Vendor— Affected before 0.0.0-20260420180337-2b2a901aa9f7 Fixed in 0.0.0-20260420180337-2b2a901aa9f7 Patch available GHSA-r65v-xgwc-g56j

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:openbao:openbao:*:*:*:*:*:*:*:*before 2.5.3Vulnerableopenbao
  • cpe:2.3:a:openbao:openbao:*:*:*:*:*:*:*:* Versions before 2.5.3 Vulnerable ·openbao

Remediation

  • Fix · CNA openbao (openbao) Fixed in 2.5.3
  • Fix · GHSA-r65v-xgwc-g56j github.com/openbao/openbao (Go) Fixed in 0.0.0-20260420180337-2b2a901aa9f7 Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-39396
  2. 2026-10-03 Alias added: GHSA-r65v-xgwc-g56j

References

Exploit 1

Advisory 1

Other 4

  • TI-2024-01904 Vault Cert Auth Method Did Not Correctly Validate Non-CA Certificates CVSS 3.1CRITICAL 9.8
  • TI-2026-26136 OpenBao lacks user confirmation for OIDC direct callback mode CVSS 3.1CRITICAL 9.6
  • TI-2026-26137 OpenBao has Reflected XSS in its OIDC authentication error message CVSS 4.0CRITICAL 9.4
  • TI-2025-34701 OpenBao: Privileged Operator May Execute Code on the Underlying Host CVSS 3.1CRITICAL 9.1
  • TI-2025-36685 OpenBao vulnerable to denial of service via malicious JSON request processing CVSS 3.1HIGH 7.5
  • TI-2024-07039 Vault SSH Secrets Engine Configuration Did Not Restrict Valid Principals By Default CVSS 3.1HIGH 8.8
See all 24 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences