VulnerabilityPublished 18 Sep 2026

CVE-2026-13666: Synology DiskStation Manager (DSM) · CRLF Injection

Affects Synology DiskStation Manager (DSM)Source CVE Database V5

Not known to be exploited · CVSS 3.5 Low · fixed in 7.4-90075 : update Synology DiskStation Manager (DSM) when convenient.

Data as of 2 Nov 2026, 22:58 UTC

CVSS 3.1 base score

3.5Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 7.4-90075, 7.3.2-86009-4, 7.2.2-72806-9 +1

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: Required
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade synology/diskstation-manager to 7.4-90075, 7.3.2-86009-4, 7.2.2-72806-9 or 7.2.1-69057-12.

Affected software

Product	Affected	Fixed in
SynologyDiskStation Manager (DSM)	Affected >=7.4 <7.4-90075 >=7.3.2 <7.3.2-86009-4 >=7.2.2 <7.2.2-72806-9 >=7.2.1 <7.2.1-69057-12	Fixed in–
Synologysynology/diskstation-manager`pkg:rpm/synology/diskstation-manager`Other threats	Affected >=7.2.1 <7.2.1-69057-12 >=7.2.2 <7.2.2-72806-9 >=7.3.2 <7.3.2-86009-4 >=7.4 <7.4-90075	Fixed in 7.2.1-69057-12 7.2.2-72806-9 7.3.2-86009-4 7.4-90075

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Fixed versions are 7.2.1-69057-12, 7.2.2-72806-9, 7.3.2-86009-4, and 7.4-90075. Users should upgrade to these or later versions to remediate the vulnerability. Patch status is confirmed by version numbers; no additional mitigation guidance is provided.

Description

An improper neutralization of CRLF sequences ('CRLF Injection') vulnerability in Sharing API in Synology DiskStation Manager (DSM) before 7.2.1-69057-12, 7.2.2-72806-9, 7.3.2-86009-4 and 7.4-90075 allows remote authenticated users to write limited files when a victim clicks a sharing URL.

Impact

An attacker with valid authentication can cause limited file writes on the system when a victim interacts with a crafted sharing URL. This may allow limited integrity modifications but does not affect confidentiality or availability. There are no known exploits in the wild.

Summary

This vulnerability involves improper neutralization of CRLF sequences in the Sharing API of Synology DSM, enabling remote authenticated users to perform limited file write operations triggered by a victim clicking a malicious sharing URL. The issue affects multiple DSM versions prior to the specified fixed builds. The CVSS 3.1 base score is 3.5, indicating low severity, with attack vector network, low attack complexity, requiring privileges and user interaction, and impacts integrity only without confidentiality or availability impact.

References

synology.com/en-global/security/advisory/Synology_SA_26_13 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 18 Sep 2026, 19:47 UTC

Technical details

References

Community reviews

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