Rsync < 3.4.3 Integer Overflow Information Disclosure
Summary
| CVE | CVE-2026-43618 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-20 02:16:36 UTC |
| Updated | 2026-06-30 03:19:47 UTC |
| Description | Rsync version 3.4.2 and prior contain an integer overflow vulnerability in the compressed-token decoder where a 32-bit signed counter is not checked for overflow, allowing a malicious sender to trigger an overflow that causes the receiver process to read and return data from outside the intended buffer bounds. Attackers can exploit this vulnerability to disclose process memory contents including environment variables, passwords, heap and stack data, and library memory pointers, significantly reducing ASLR effectiveness and facilitating further exploitation. |
Risk And Classification
Primary CVSS: v4.0 6.1 MEDIUM from [email protected]
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/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: 0.007800000 probability, percentile 0.514650000 (date 2026-07-04)
Problem Types: CWE-125 | CWE-190 | CWE-190 Integer Overflow or Wraparound | CWE-125 Out-of-bounds Read
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 6.1 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 6.1 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N |
| 3.1 | ADP | CVSS | 8.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | [email protected] | Primary | 8.1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 8.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 8.1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/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
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | RsyncProject | Rsync | affected 3.4.3 semver | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux AppStream V. 10 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux AppStream V. 9 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux BaseOS V. 10 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux BaseOS V. 8 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux BaseOS V. 9 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Discovery 2 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| ADP | Red Hat | Red Hat OpenShift Container Platform 4 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:26408 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26410 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:26332 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | |
| access.redhat.com/errata/RHSA-2026:29197 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43618.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | |
| github.com/RsyncProject/rsync/releases/tag/v3.4.3 | [email protected] | github.com | Release Notes |
| github.com/RsyncProject/rsync/security/advisories/GHSA-g37v-g3gj-pmwq | [email protected] | github.com | Vendor Advisory |
| access.redhat.com/security/cve/CVE-2026-43618 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | |
| www.vulncheck.com/advisories/rsync-integer-overflow-information-disclosure | [email protected] | www.vulncheck.com | Third Party Advisory |
| 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: Omar Elsayed (@seks99x) (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-05-11T13:09:39.838Z | Reported to Red Hat. |
| ADP | 2026-05-20T00:00:00.000Z | Made public. |
Solutions
ADP: RHSA-2026:26332: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10)
ADP: RHSA-2026:26410: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9)
ADP: RHSA-2026:26408: Red Hat Enterprise Linux BaseOS (v. 8)
ADP: RHSA-2026:29197: Red Hat Discovery 2
Workarounds
ADP: Disable compression on the rsync daemon by adding `refuse options = compress` to the `rsyncd.conf` file. A restart of the rsync daemon service is required for the change to take effect and may impact transfer performance.