CVE-2026-75834

MEDIUMPre-NVD 5.45.4—
EchelonGraph scoreHIGH confidence

Score 5.4 from GitHub Security Advisory published 2026-08-18. a secondary CVSS source baseline 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.4Exploit: None knownExposed: 0

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

Grav before 2.0.14 contains a stored cross-site scripting vulnerability in the Security::detectXss() function (system/src/Grav/Common/Security.php). All XSS detection patterns use the PCRE /u (UTF-8) modifier, so a single invalid UTF-8 byte anywhere in page content causes preg_match() to return false for every pattern, silently bypassing the save-time XSS safety gate (Validation::checkSafety()). An authenticated attacker with page-edit permissions (without the security.xss_whitelist privilege) can store malicious JavaScript that executes in the browser of a visitor who views the affected page.

CVSS v3
5.4
EG Score
5.4(high)
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 computed
Severity54% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
8%
KEV
Not listed

Published

August 18, 2026

Last Modified

August 18, 2026

Advisory Details (2)

Auto-updated Aug 18, 2026
Patch available. Sources: github.
generic

Grav before 2.0.14 Stored XSS via Invalid UTF-8 Byte | Advisories | VulnCheck

https://www.vulncheck.com/advisories/grav-before-stored-xss-via-invalid-utf-8-byte
github Patch Available

Single invalid UTF-8 byte disables every rule in Security::detectXss(), bypassing the page-content XSS safety gate · Advisory · getgrav/grav · GitHub

https://github.com/getgrav/grav/security/advisories/GHSA-q2j8-x8hf-63ch

Vendor Advisories for CVE-2026-75834(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 13× 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. 2026-08-20 22:56 UTCEPSS rescore
  2. 2026-08-20 15:50 UTCEG score recompute
  3. 2026-08-20 15:50 UTCGHSA enrichment
  4. 2026-08-19 17:04 UTCEPSS rescore
  5. 2026-08-19 15:19 UTCGHSA enrichment
  6. 2026-08-18 14:47 UTCEG score recompute
  7. 2026-08-18 14:46 UTCGHSA enrichment
  8. 2026-08-18 13:48 UTCEG score recompute
  9. 2026-08-18 13:48 UTCGHSA enrichment
  10. 2026-08-18 12:34 UTCEG score recompute
  11. 2026-08-18 12:34 UTCGHSA enrichment
  12. 2026-08-18 11:29 UTCEG score recompute
  13. 2026-08-18 11:29 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-75834?
CVE-2026-75834 is a medium vulnerability published on August 18, 2026. Grav before 2.0.14 contains a stored cross-site scripting vulnerability in the Security::detectXss() function (system/src/Grav/Common/Security.php). All XSS detection patterns use the PCRE /u (UTF-8) modifier, so a single invalid UTF-8 byte anywhere in page content causes pregmatch() to return…
When was CVE-2026-75834 disclosed?
CVE-2026-75834 was first published in the National Vulnerability Database on August 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-75834 actively exploited?
CVE-2026-75834 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 91.9% of all scored CVEs.
What is the CVSS score of CVE-2026-75834?
CVE-2026-75834 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2026-75834?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-75834, 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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