Contacts app for Nextcloud easily syncs contacts from various devices with your Nextcloud and allows editing. Prior to 5.5.4, 6.0.6, and 7.2.5, a malicious user was able to modify their organisation and title field to load additional CSS files. Javascript and other options were correctly blocked by the content security policy of the Nextcloud Server code. This vulnerability is fixed in 5.5.4, 6.0.6, and 7.2.5.
CVE-2025-66554
This medium-severity CVE scores 5.4 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 88% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.4
- EG Score
- 5.4(medium)
- EG Risk
- 24(Track)EG Risk 24/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity54% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 16%
- KEV
- Not listed
Published
December 5, 2025
Last Modified
June 17, 2026
References (4)
- security-advisories@githubhttps://github.com/nextcloud/contacts/commit/d954d098978dde1f121600e8b994e02f293c68b1
- security-advisories@githubhttps://github.com/nextcloud/contacts/pull/4619
- security-advisories@githubhttps://github.com/nextcloud/security-advisories/security/advisories/GHSA-9v78-cpfc-v6h2
- security-advisories@githubhttps://hackerone.com/reports/3293290
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 40× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 107 total refreshes for this CVE.
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-04 15:09 UTCEPSS rescore
- 2026-08-04 10:37 UTCEPSS rescore
- 2026-08-03 10:35 UTCEPSS rescore
- 2026-08-02 02:26 UTCEPSS rescore
- 2026-08-01 04:15 UTCEPSS rescore
- 2026-07-30 16:27 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-28 15:35 UTCEPSS rescore
- 2026-07-27 14:12 UTCEPSS rescore
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-25 14:17 UTCEPSS rescore
- 2026-07-24 14:17 UTCEPSS rescore
- 2026-07-24 14:17 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 13:49 UTCOSV refresh
- 2026-07-23 03:01 UTCEG score recompute▲ 1.90
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:30 UTCEPSS rescore
- 2026-07-19 14:30 UTCEPSS rescore
Show 75 moreShow fewer
- 2026-07-19 02:28 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-16 17:02 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 01:59 UTCEPSS rescore
- 2026-07-15 01:59 UTCEPSS rescore
- 2026-07-13 22:29 UTCEPSS rescore
- 2026-07-13 06:12 UTCEPSS rescore
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-09 19:09 UTCEPSS rescore
- 2026-07-08 15:15 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 08:41 UTCOSV refresh
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-04 06:30 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-28 14:07 UTCEPSS rescore
- 2026-06-28 14:07 UTCEPSS rescore
- 2026-06-28 04:56 UTCEPSS rescore
- 2026-06-28 04:55 UTCEPSS rescore
- 2026-06-27 03:08 UTCEPSS rescore
- 2026-06-25 13:49 UTCEPSS rescore
- 2026-06-24 14:04 UTCEPSS rescore
- 2026-06-24 14:04 UTCEPSS rescore
- 2026-06-24 10:01 UTCNVD updateCVSS v3 → 5.4 · severity → MEDIUM
- 2026-06-23 21:32 UTCEPSS rescore
- 2026-06-23 21:32 UTCEPSS rescore
- 2026-06-22 14:25 UTCEPSS rescore
- 2026-06-21 14:56 UTCEPSS rescore
- 2026-06-21 14:56 UTCEPSS rescore
- 2026-06-21 01:59 UTCEPSS rescore
- 2026-06-21 01:59 UTCEPSS rescore
- 2026-06-19 19:25 UTCEPSS rescore
- 2026-06-19 19:25 UTCEPSS rescore
- 2026-06-17 20:35 UTCOSV refresh
- 2026-06-17 17:52 UTCEPSS rescore
- 2026-06-16 17:52 UTCEPSS rescore
- 2026-06-15 17:48 UTCEPSS rescore
- 2026-06-15 17:48 UTCEPSS rescore
- 2026-06-14 23:18 UTCEPSS rescore
- 2026-06-13 23:00 UTCEPSS rescore
- 2026-06-13 23:00 UTCEPSS rescore
- 2026-06-12 23:11 UTCEPSS rescore
- 2026-06-11 14:00 UTCEPSS rescore
- 2026-06-10 22:18 UTCEPSS rescore
- 2026-06-10 22:18 UTCEPSS rescore
- 2026-06-10 13:22 UTCEPSS rescore
- 2026-06-08 14:17 UTCEPSS rescore
- 2026-06-08 14:16 UTCEPSS rescore
- 2026-06-07 15:24 UTCEPSS rescore
- 2026-06-07 15:24 UTCEPSS rescore
- 2026-06-06 13:47 UTCEPSS rescore
- 2026-06-06 13:47 UTCEPSS rescore
- 2026-06-05 22:46 UTCEPSS rescore
- 2026-06-05 22:46 UTCEPSS rescore
- 2026-06-05 06:10 UTCEPSS rescore
- 2026-06-05 06:10 UTCEPSS rescore
- 2026-06-04 13:12 UTCEPSS rescore
- 2026-06-04 13:12 UTCEPSS rescore
- 2026-06-02 20:13 UTCEPSS rescore
- 2026-06-02 20:12 UTCEPSS rescore
- 2026-06-01 13:51 UTCEPSS rescore
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2025-66554?
When was CVE-2025-66554 disclosed?
Is CVE-2025-66554 actively exploited?
What is the CVSS score of CVE-2025-66554?
How do I remediate CVE-2025-66554?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2025-66554
Is Your Infrastructure Affected by CVE-2025-66554?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.