Barman snapshot backup deletion trusts unverified backup catalog metadata
Summary
| CVE | CVE-2026-93853 |
|---|---|
| State | PUBLISHED |
| Assigner | EDB |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-29 21:19:39 UTC |
| Updated | 2026-09-30 19:57:08 UTC |
| Description | Unverified ownership in Barman snapshot backup deletion allows a principal who can write the backup catalog to cause Barman to delete unrelated cloud snapshots. When a snapshot backup is deleted, either explicitly or by retention policy enforcement, Barman reads the snapshot identifiers from the backup.info file and passes them to the cloud provider's delete API using Barman's own credentials, without verifying that the snapshots belong to that backup. An attacker who can overwrite backup.info but lacks snapshot delete permissions can substitute the identifiers of other snapshots, causing Barman to delete any snapshot its cloud identity can reach on AWS, Microsoft Azure, or Google Cloud. Exploitation requires a deployment where the principal that writes the backup catalog is separate from the identity Barman uses to delete snapshots. Barman versions from 3.4.0 (Google Cloud), 3.6.0 (Azure), and 3.7.0 (AWS) up to and including 3.20.0 are affected. The issue is fixed in Barman 3.20.1. |
Risk And Classification
Primary CVSS: v4.0 7.2 HIGH from 20be33e2-bf35-4d13-8fad-18bd2f3e3659
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.002070000 probability, percentile 0.097350000 (date 2026-10-01)
Problem Types: CWE-283 | CWE-283 CWE-283 Unverified Ownership
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 20be33e2-bf35-4d13-8fad-18bd2f3e3659 | Secondary | 7.2 | HIGH | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H/E:X/C... |
| 4.0 | CNA | CVSS | 7.2 | HIGH | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | EnterpriseDB | Barman | affected 3.4.0 3.20.1 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.enterprisedb.com/docs/security/advisories/cve202693853 | 20be33e2-bf35-4d13-8fad-18bd2f3e3659 | www.enterprisedb.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Mufeed VH of Winfunc (en)
Additional Advisory Data
Solutions
CNA: Upgrade to Barman 3.20.1 or later. Before deleting a snapshot, Barman now reads the snapshot name from the cloud provider and refuses the deletion unless it matches the backup being deleted.
Workarounds
CNA: Restrict write access to the backup catalog in object storage to the identity Barman uses. Enable object versioning or object lock on the backup bucket, and on AWS use EBS Snapshot Lock (aws_snapshot_lock_mode) to protect snapshots from deletion.