CVE-2026-45279 [Medium] | Path Traversal in Nextcloud Server

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 31.0.0 to before 31.0.14, and 32.0.0 to before 32.0.4, if {lang} is used in the template directory config value, non-admin users can in some cases copy arbitrary files (depending on unix permissions) into their own Nextcloud directory via a path traversal. It is recommended that the Nextcloud Server is upgraded to 32.0.4, 31.0.14. It is recommended that the Nextcloud Enterprise Server is upgraded to 32.0.4, 31.0.14, 30.0.17.7, 29.0.17.12, 28.0.14.15

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-02	—	0.03%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-02

—

0.03%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
4.4	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:H) They need powerful rights—admin, root, or similar—before this pays off. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.	0.7	3.6	[email protected]
6.5	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.	2.8	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

4.4

3.1

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H): They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:N): Service keeps running; no real outage angle.

0.7

3.6

[email protected]

6.5

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:N): Service keeps running; no real outage angle.

2.8

3.6

[email protected]

Affected software / configurations for CVE-2026-45279

Vendor	Product	Version	Raw CPE
nextcloud	nextcloud_server	>= 31.0.0, < 31.0.14	cpe:2.3:a:nextcloud:nextcloud_server:::::-:::*
nextcloud	nextcloud_server	>= 32.0.0, < 32.0.4	cpe:2.3:a:nextcloud:nextcloud_server:::::-:::*
nextcloud	nextcloud_server	>= 28.0.0, < 28.0.14.15	cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*
nextcloud	nextcloud_server	>= 29.0.0, < 29.0.17.12	cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*
nextcloud	nextcloud_server	>= 30.0.0, < 30.0.17.7	cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*
nextcloud	nextcloud_server	>= 31.0.0, < 31.0.14	cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*
nextcloud	nextcloud_server	>= 32.0.0, < 32.0.4	cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*

References for CVE-2026-45279

URL	Tags
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-j33j-qph5-4wch	Mitigation Vendor Advisory
https://github.com/nextcloud/server/pull/57414/files	Issue Tracking Patch
https://hackerone.com/reports/3468140	Permissions Required

URL

CVE-2026-45279 | Nextcloud: Limited path traversal via template API if using `{lang}` in config

Exploit prediction scoring system (EPSS) score for CVE-2026-45279

Common vulnerability scoring system (CVSS) metrics for CVE-2026-45279

Weakness enumeration for CVE-2026-45279

Affected software / configurations for CVE-2026-45279

References for CVE-2026-45279