# CVE-2023-36811: borgbackup: borgbackup is an opensource, deduplicating archiver with compression and authenticated encryption

CVE-2023-36811 is fixed in borgbackup on 1 platform, first by DEBIAN-CVE-2023-36811, released August 30, 2023. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2023-36811
- Priority: Routine
- CVSS: 4.7 (medium)
- EPSS: 0.0011
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 30, 2023

## Description

borgbackup is an opensource, deduplicating archiver with compression and authenticated encryption. A flaw in the cryptographic authentication scheme in borgbackup allowed an attacker to fake archives and potentially indirectly cause backup data loss in the repository. The attack requires an attacker to be able to: 1. insert files (with no additional headers) into backups and 2. gain write access to the repository. This vulnerability does not disclose plaintext to the attacker, nor does it affect the authenticity of existing archives. Creating plausible fake archives may be feasible for empty or small archives, but is unlikely for large archives. The issue has been fixed in borgbackup 1.2.5. Users are advised to upgrade. Additionally to installing the fixed code, users must follow the upgrade procedure as documented in the change log. Data loss after being attacked can be avoided by reviewing the archives (timestamp and contents valid and as expected) after any "borg check --repair" and before "borg prune". There are no known workarounds for this vulnerability.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | borgbackup Debian 13.5 (trixie) | 1.2.5-1 | [DEBIAN-CVE-2023-36811](https://patchblox.com/security/data/fix/linux/debian-cve-2023-36811.md) | Aug 30, 2023 |
| Linux | borgbackup Debian 14 | 1.2.5-1 | [DEBIAN-CVE-2023-36811](https://patchblox.com/security/data/fix/linux/debian-cve-2023-36811.md) | Aug 30, 2023 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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