High-severity remote arbitrary file read/write + DoS in Synology DSM, a widely deployed NAS platform; can expose or alter enterprise data and disrupt services — fixed versions released.
CVE-2026-13684
Critical remote arbitrary file read/write and DoS in Synology DSM via SCGI
Is CVE-2026-13684 being exploited?
Not confirmed. CVE-2026-13684 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.60% probability of exploitation in the next 30 days.
How severe is CVE-2026-13684?
CVE-2026-13684 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-13684?
Yes. A fix has been recorded for CVE-2026-13684. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-13684 affect?
CVE-2026-13684 affects Synology DiskStation Manager (DSM) prior to 7.2.1-69057-12, DSM prior to 7.2.2-72806-9, DSM prior to 7.3.2-86009-4, DSM prior to 7.4-90075. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-13684?
Apply Synology DSM updates to the fixed versions immediately; validate integrity and rotate credentials.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attackers can read/write arbitrary files and cause DoS via SCGI, enabling data theft, tampering, and potential follow-on compromise.
Immediate action required
- affected>= 7.4 and < 7.4-90075
- affected>= 7.3.2 and < 7.3.2-86009-4
- affected>= 7.2.2 and < 7.2.2-72806-9
- affected>= 7.2.1 and < 7.2.1-69057-12
- affected< 7.2.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
public exploits
Unvetted proof-of-concept code on GitHub: 1 GitHub proof of concept
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
cisa ssvc
- exploitation
- none
- automatable
- yes
- technical impact
- total
Assessed by CISA 18 Sept 2026 (SSVC 2.0.3).
timeline
- 18 Sept 2026Published
- 18 Sept 2026CISA SSVC assessment: exploitation none · same day later
- 18 Sept 2026CVE record last updated · same day later
- 20 Sept 2026Analysed by vulneraibility.com · 2 days later
- 30 Oct 2026First proof-of-concept repository on GitHub (unvetted) · 39 days later
- Linksynology.com /en-global/security/advisory/Synology_SA_26_13
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.