CVE-2026-70454: rsyncproject rsync Improper Certificate Validation
Vulnerability summary
CVE-2026-70454 is a high (CVSS 8.0) Improper Certificate Validation vulnerability in rsyncproject rsync. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8.1% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 11 · Related 8Timeline
- 13-08-2026PublishedVulnerability first disclosed.
- 14-08-2026Last modifiedVulnerability information updated.
Description
rsync 3.2.0 through 3.2.3 (openssl mode) and rsync-ssl through 3.4.4 (stunnel mode) contain a TLS certificate validation vulnerability that allows on-path attackers to intercept encrypted sessions by presenting self-signed or otherwise invalid certificates. Attackers can exploit the failure to validate server TLS certificates against a trusted CA or verify certificate hostname matching to decrypt or tamper with rsync session content without detection by the client.
CVSS metrics
8 scores · 5 sources · 2 versions- OSV · AlpineEcosystem advisory · calculated7.6HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/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
- OSV · UbuntuEcosystem advisory · calculated7.6HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- OSV · DebianEcosystem advisory · calculated7.6HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/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
- NVDNIST7.6HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/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
- OSV · UbuntuEcosystem advisory · calculated8.0HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
- NVDNIST8.0HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
EPSS trend
Probability
0.19%
Chance of exploitation in the next 30 days
Percentile
8%
Versus all other CVEs
30-day change
0.00 pp
From 0.19% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Alpine1 product
- rsync< 3.5.0-r0
Debian1 product
- rsyncAll versions (No fix recorded) | < 3.5.0+ds1-0+deb13u1 | < 3.5.0+ds1-1
Rsyncproject1 product
- rsync≤ 3.4.4
Ubuntu1 product
- rsyncAll versions (No fix recorded)
4 vendors · 4 products
References
9 links- github.com/RsyncProject/rsync/releases/tag/v3.5.0Release Notes
