CVE-2026-48821

MEDIUMPre-NVD 5.85.8—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 97% 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).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.8
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Shaarli is a personal bookmarking service. Versions 0.16.1 and prior contain a DOM-based Cross-Site Scripting (XSS) vulnerability in the Thumbnail Synchronizer feature. When an administrator runs the thumbnail update process, malicious bookmark titles are returned via an AJAX response and inserted into the DOM using innerHTML without proper sanitization. The issue originates from the interaction between the backend thumbnail update endpoint and the frontend JavaScript responsible for rendering update progress. On the backend, the ThumbnailsController::ajaxUpdate method returns bookmark data formatted using the 'raw' formatter. This includes the unescaped bookmark title in the JSON response. On the client side, the script thumbnails-update.js processes this AJAX response and dynamically updates the progress interface. Administrators using the thumbnail synchronization feature are affected and exploitation could lead to session hijacking, privilege escalation, backdoor injection and full compromise. This issue has been fixed in version 0.16.2.

CVSS v3
5.8
EG Score
5.8(medium)
EPSS
3.0%
KEV
Not listed

Published

June 17, 2026

Last Modified

June 23, 2026

Advisory Details (2)

Auto-updated Jun 17, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github.
github Patch Available🟡 PoC Available

DOM-based Cross-Site Scripting (XSS) in Thumbnail Synchronizer · Advisory · shaarli/Shaarli · GitHub

https://github.com/shaarli/Shaarli/security/advisories/GHSA-mw63-f9qj-c5h3
github_release Patch Available

v0.16.2

Patch available: shaarli/Shaarli v0.16.2

https://github.com/shaarli/Shaarli/releases/tag/v0.16.2

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 14× in last 7d / 61× 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.

  1. 2026-07-15 21:31 UTCEG score recompute
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 02:00 UTCEPSS rescore
  4. 2026-07-14 19:43 UTCEG score recompute
  5. 2026-07-13 22:30 UTCEPSS rescore
  6. 2026-07-13 17:26 UTCEG score recompute
  7. 2026-07-13 06:13 UTCEPSS rescore
  8. 2026-07-12 15:38 UTCEG score recompute
  9. 2026-07-12 05:46 UTCEPSS rescore
  10. 2026-07-11 13:47 UTCEG score recompute
  11. 2026-07-11 08:27 UTCEPSS rescore
  12. 2026-07-10 11:59 UTCEG score recompute
  13. 2026-07-09 19:10 UTCEPSS rescore
  14. 2026-07-09 10:10 UTCEG score recompute
  15. 2026-07-08 15:16 UTCEPSS rescore
  16. 2026-07-08 08:21 UTCEG score recompute
  17. 2026-07-07 13:46 UTCEPSS rescore
  18. 2026-07-07 06:30 UTCEG score recompute
  19. 2026-07-06 16:27 UTCEPSS rescore
  20. 2026-07-06 04:39 UTCEG score recompute
  21. 2026-07-06 02:23 UTCEPSS rescore
  22. 2026-07-05 02:49 UTCEG score recompute
  23. 2026-07-04 06:31 UTCEPSS rescore
  24. 2026-07-04 01:01 UTCEG score recompute
  25. 2026-07-02 23:13 UTCEG score recompute
Show 36 more
  1. 2026-07-01 21:25 UTCEG score recompute
  2. 2026-07-01 15:07 UTCEPSS rescore
  3. 2026-06-30 19:37 UTCEG score recompute
  4. 2026-06-29 17:50 UTCEG score recompute
  5. 2026-06-29 14:06 UTCEPSS rescore
  6. 2026-06-29 14:06 UTCEPSS rescore
  7. 2026-06-28 16:02 UTCEG score recompute
  8. 2026-06-28 14:07 UTCEPSS rescore
  9. 2026-06-28 04:56 UTCEPSS rescore
  10. 2026-06-28 04:56 UTCEPSS rescore
  11. 2026-06-27 14:14 UTCEG score recompute
  12. 2026-06-27 03:08 UTCEPSS rescore
  13. 2026-06-26 12:26 UTCEG score recompute
  14. 2026-06-25 13:49 UTCEPSS rescore
  15. 2026-06-25 10:38 UTCEG score recompute
  16. 2026-06-24 14:05 UTCEPSS rescore
  17. 2026-06-24 08:50 UTCEG score recompute
  18. 2026-06-23 21:33 UTCEPSS rescore
  19. 2026-06-23 21:33 UTCEPSS rescore
  20. 2026-06-23 07:03 UTCEG score recompute
  21. 2026-06-22 14:25 UTCEPSS rescore
  22. 2026-06-22 14:25 UTCEPSS rescore
  23. 2026-06-22 05:13 UTCEG score recompute
  24. 2026-06-21 14:56 UTCEPSS rescore
  25. 2026-06-21 14:56 UTCEPSS rescore
  26. 2026-06-21 03:24 UTCEG score recompute
  27. 2026-06-21 01:59 UTCEPSS rescore
  28. 2026-06-21 01:59 UTCEPSS rescore
  29. 2026-06-20 01:30 UTCEG score recompute
  30. 2026-06-19 19:26 UTCEPSS rescore
  31. 2026-06-19 19:26 UTCEPSS rescore
  32. 2026-06-18 23:40 UTCEG score recompute
  33. 2026-06-18 17:52 UTCEPSS rescore
  34. 2026-06-18 17:52 UTCEPSS rescore
  35. 2026-06-17 21:51 UTCEG score recompute
  36. 2026-06-17 21:51 UTCNVD updatefirst tracked

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Frequently asked(5)

What is CVE-2026-48821?
CVE-2026-48821 is a medium vulnerability published on June 17, 2026. Shaarli is a personal bookmarking service. Versions 0.16.1 and prior contain a DOM-based Cross-Site Scripting (XSS) vulnerability in the Thumbnail Synchronizer feature. When an administrator runs the thumbnail update process, malicious bookmark titles are returned via an AJAX response and inserted…
When was CVE-2026-48821 disclosed?
CVE-2026-48821 was first published in the National Vulnerability Database on June 17, 2026, with the most recent update on June 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-48821 actively exploited?
CVE-2026-48821 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-48821?
CVE-2026-48821 has a CVSS v3 base score of 5.8 (NVD).
How do I remediate CVE-2026-48821?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-48821, 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.

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