Vulnerability in rsync (DEBIAN-CVE-2026-44508)

Summary

Vulnerability in rsync (DEBIAN-CVE-2026-44508). Confidential information can be exposed externally. Mitigation: upgrade to 3.4.3+ds1-1 or later.

Original description

The description as published by the source.

Rsync is a file-copying tool that uses a delta-transfer algorithm to synchronize remote and local files. In versions prior to 3.4.3, the receiver's compressed-token decoder accumulated a 32-bit signed counter without checking for overflow. A malicious sender can trigger an overflow that with careful manipulation can lead to the extraction of data stored in memory of the process allowing an attacker to access environment variables, passwords and memory pointers from the heap, stack, and libraries. The leakage of these pointers and data can significantly reduce the effectiveness of ASLR and facilitate further exploitation. This issue is fixed in version 3.4.3.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as DEBIAN-CVE-2026-44508 has been found in rsync.
Confidential information can be exposed externally.
What to do: upgrade rsync to 3.4.3+ds1-1 or later.
If unsure, ask your IT team or search "rsync DEBIAN-CVE-2026-44508" on the vendor's site.

DEBIAN-CVE-2026-44508 (rsync)
Attack vector: remote (network-reachable) / no user interaction
Patched: 3.4.3+ds1-1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in rsync.

📍 Affected scope

Check the vendor advisory for the affected versions of rsync.

🔥 Severity

Severity: ?. Confidential information can be exposed externally.

🔧 How to fix

Update to 3.4.3+ds1-1.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'rsync' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'rsync' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で rsync を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade rsync to 3.4.3+ds1-1
```
ステージング環境で 3.4.3+ds1-1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Debian:11 rsync

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Debian:12 rsync

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Debian:13 rsync

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Debian:14 rsync

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.4.3+ds1-1"}]}]

References

advisory security-tracker.debian.org