No exploitation reportedFix available

CVE-2021-29085

Q: Is CVE-2021-29085 actively exploited?

Active exploitation of CVE-2021-29085 has not been confirmed. Its EPSS score was 1.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-29085?

CVE-2021-29085 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

No exploitation reported by the sources we read.

Published2021-06-23
Fixed in6.2.3-25426-3
WeaknessCWE-74

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Improper neutralization of special elements in output used by a downstream component ('Injection') vulnerability in file sharing management component in Synology DiskStation Manager (DSM) before 6.2.3-25426-3 allows remote attackers to read arbitrary files via unspecified vectors.

Timeline

dates in UTC

2021-06-2310:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-29085?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-29085?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Synology diskstation manager

Branch	Affected	Fixed in	Source
6.2	≥ 6.2, < 6.2.3-25426-3	6.2.3-25426-3	NVD

Synology diskstation manager unified controller

Branch	Affected	Fixed in	Source
3.1	< 3.1-23033	3.1-23033	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Synology diskstation manager to 6.2.3-25426-3

Advisories and patches

www.synology.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CNACVSS 3.18.6read 2026-10-23
NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
CNAweakness (CWE)CWE-74read 2026-10-23
FIRST EPSSEPSS score1.3 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Published: 2021-06-23
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-29085?

Is CVE-2021-29085 actively exploited?

Active exploitation of CVE-2021-29085 has not been confirmed. Its EPSS score was 1.3% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-29085?

CVE-2021-29085 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

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