CVE-2026-63135

HIGHPre-NVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 84% 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
Elevated
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.2Exploit: Elevated riskExposed: 0

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

YOURLS is a self-hosted, customizable URL shortener written in PHP. From 1.5.1 until 1.10.4, YOURLS stores the HTTP Referer header through yourls_get_referrer(), yourls_sanitize_url_safe(), and yourls_log_redirect(), then aggregates the value in yourls-infos.php and passes the derived domain through yourls_get_domain(), yourls_stats_pie(), and yourls_google_array_to_data_table(). The chart builder concatenates labels into inline JavaScript without JavaScript-string escaping, so an unauthenticated attacker can poison the statistics of an existing short URL with a crafted referrer. When an administrator or public stats-page viewer opens the affected statistics page, attacker-controlled JavaScript executes in the YOURLS origin and can access admin-visible data, the API signature token, and privileged same-origin actions. This issue is fixed in version 1.10.4.

CVSS v3
8.2
EG Score
8.2(medium)
EG Risk
53(Track)
EG Risk 53/100SSVC: 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 computed
Severity82% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
KEV
Not listed

Published

August 21, 2026

Last Modified

August 26, 2026

Advisory Details (4)

Auto-updated Aug 21, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github, github_pr, github_commit.
github_release Patch Available

1.10.4

Patch available: YOURLS/YOURLS 1.10.4

https://github.com/YOURLS/YOURLS/releases/tag/1.10.4
github_commit Patch Available

commit e1e934766551 (YOURLS/YOURLS)

Patch available: YOURLS/YOURLS 1.10.4 (contains commit e1e934766551)

https://github.com/YOURLS/YOURLS/commit/e1e93476655107e6caab34e52259eb1c91079ec7
github_pr Patch Available

Prevent XSS in stat pages through referrers

Patch available: YOURLS/YOURLS 1.10.4 (PR #4107 merged 2026-05-21)

https://github.com/YOURLS/YOURLS/pull/4107
github Patch Available🟡 PoC Available

Stored XSS in referrer statistics chart via crafted Referer header · Advisory · YOURLS/YOURLS · GitHub

https://github.com/YOURLS/YOURLS/security/advisories/GHSA-5h77-88j3-r659

Vendor Advisories for CVE-2026-63135(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
yourls/yourls1.10.0 ... 1.9.2 (17 versions)1.10.4—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 16× 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. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 01:27 UTCEG score recompute
  3. 2026-08-28 21:42 UTCEPSS rescore
  4. 2026-08-27 16:27 UTCEG score recompute
  5. 2026-08-27 14:25 UTCEPSS rescore
  6. 2026-08-26 18:24 UTCEG score recompute
  7. 2026-08-26 18:06 UTCEG score recompute
  8. 2026-08-26 14:46 UTCEPSS rescore
  9. 2026-08-26 00:18 UTCEG score recompute
  10. 2026-08-25 13:49 UTCEPSS rescore
  11. 2026-08-24 15:18 UTCEG score recompute
  12. 2026-08-23 06:20 UTCEG score recompute
  13. 2026-08-23 00:19 UTCEPSS rescore
  14. 2026-08-21 21:24 UTCEG score recompute
  15. 2026-08-21 20:44 UTCEG score recompute
  16. 2026-08-21 20:44 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-63135?
CVE-2026-63135 is a high vulnerability published on August 21, 2026. YOURLS is a self-hosted, customizable URL shortener written in PHP. From 1.5.1 until 1.10.4, YOURLS stores the HTTP Referer header through yourlsgetreferrer(), yourlssanitizeurlsafe(), and yourlslogredirect(), then aggregates the value in yourls-infos.php and passes the derived domain through…
When was CVE-2026-63135 disclosed?
CVE-2026-63135 was first published in the National Vulnerability Database on August 21, 2026, with the most recent update on August 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63135 actively exploited?
CVE-2026-63135 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 84.2% of all scored CVEs.
What is the CVSS score of CVE-2026-63135?
CVE-2026-63135 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-63135?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63135, 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

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