Evidence-led vulnerability intelligence · 2026-09-30 02:49 IST

CVE-2026-93853

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.

Executive briefing

The source record describes: 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. The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.

Assessment: Potential exposure only — validate the installed product, exact version, configuration and vendor applicability before treating an asset as confirmed vulnerable.

Evidence confidence: Low Evidence-derived, not an exploitability verdict

Severity & attack characteristics

7.2 / 10 · 4.0

CVSS vector:
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

Attack vectorN
Attack complexityL
Attack requirementsP
Privileges requiredL
User interactionN
ScopeX

Technical explanation & impact

The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.

Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.

Weakness classification

CWE-283

Affected products and versions

NVD has not supplied machine-readable vulnerable CPE product/version entries for this CVE. This is an information gap, not proof that no products are affected. Check the vendor advisory references below.

Remediation & validation

  1. Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
  2. Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
  3. Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
  4. Validate the remediation with a version check and vulnerability rescan, then retain change evidence.

No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.

Vendor advisories, patches & exploit references

Information gaps & confidence notes

These gaps indicate missing source data. CVE Watch does not fill them with guessed product, exploit or patch details.

Last enrichment: 2026-11-03T07:46:14+00:00 · Source last modified: 2026-09-30T19:57:08.043

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