Nextcloud Server before 9.0.52 & ownCloud Server before 9.0.4 are vulnerable to a log pollution vulnerability potentially leading to a local XSS. The download log functionality in the admin screen is delivering the log in JSON format to the end-user. The file was delivered with an attachment disposition forcing the browser to download the document. However, Firefox running on Microsoft Windows would offer the user to open the data in the browser as an HTML document. Thus any injected data in the log would be executed.
CVE-2016-9459
MEDIUMNVD 6.16.1—
EchelonGraph scoreMEDIUM confidence
Score 6.1 from GitHub Security Advisory published 2022-05-13. NVD baseline CVSS 6.1; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
6.1
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 6.1Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.1
- EG Score
- 6.1(medium)
- EPSS
- 71.1%
- KEV
- Not listed
Published
March 28, 2017
Last Modified
May 13, 2026
References (16)
- support@hackeronehttp://www.securityfocus.com/bid/97284
- support@hackeronehttps://github.com/nextcloud/server/commit/94975af6db1551c2d23136c2ea22866a5b416070
- support@hackeronehttps://github.com/owncloud/core/commit/044ee072a647636b1a17c89265c7233b35371335
- support@hackeronehttps://github.com/owncloud/core/commit/b7fa2c5dc945b40bc6ed0a9a0e47c282ebf043e1
- support@hackeronehttps://github.com/owncloud/core/commit/efa35d621dc7ff975468e636a5d1c153511296dc
- support@hackeronehttps://hackerone.com/reports/146278
- support@hackeronehttps://nextcloud.com/security/advisory/?id=nc-sa-2016-002
- support@hackeronehttps://owncloud.org/security/advisory?id=oc-sa-2016-012
- af854a3a-2127-422b-91ae-364da2661108http://www.securityfocus.com/bid/97284
- af854a3a-2127-422b-91ae-364da2661108https://github.com/nextcloud/server/commit/94975af6db1551c2d23136c2ea22866a5b416070
- af854a3a-2127-422b-91ae-364da2661108https://github.com/owncloud/core/commit/044ee072a647636b1a17c89265c7233b35371335
- af854a3a-2127-422b-91ae-364da2661108https://github.com/owncloud/core/commit/b7fa2c5dc945b40bc6ed0a9a0e47c282ebf043e1
- af854a3a-2127-422b-91ae-364da2661108https://github.com/owncloud/core/commit/efa35d621dc7ff975468e636a5d1c153511296dc
- af854a3a-2127-422b-91ae-364da2661108https://hackerone.com/reports/146278
- af854a3a-2127-422b-91ae-364da2661108https://nextcloud.com/security/advisory/?id=nc-sa-2016-002
Frequently asked(5)
What is CVE-2016-9459?
CVE-2016-9459 is a medium vulnerability published on March 28, 2017. Nextcloud Server before 9.0.52 & ownCloud Server before 9.0.4 are vulnerable to a log pollution vulnerability potentially leading to a local XSS. The download log functionality in the admin screen is delivering the log in JSON format to the end-user. The file was delivered with an attachment…
When was CVE-2016-9459 disclosed?
CVE-2016-9459 was first published in the National Vulnerability Database on March 28, 2017, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2016-9459 actively exploited?
CVE-2016-9459 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 71.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2016-9459?
CVE-2016-9459 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2016-9459?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2016-9459, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2016-9459
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