CVE-2026-30838

MEDIUMNVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.1 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).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: None knownExposed: 0

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

league/commonmark is a PHP Markdown parser. Prior to version 2.8.1, the DisallowedRawHtml extension can be bypassed by inserting a newline, tab, or other ASCII whitespace character between a disallowed HTML tag name and the closing >. For example, would pass through unfiltered and be rendered as a valid HTML tag by browsers. This is a cross-site scripting (XSS) vector for any application that relies on this extension to sanitize untrusted user input. All applications using the DisallowedRawHtml extension to process untrusted markdown are affected. Applications that use a dedicated HTML sanitizer (such as HTML Purifier) on the rendered output are not affected. This issue has been patched in version 2.8.1.

CVSS v3
6.1
EG Score
6.1(medium)
EG Risk
32(Track)
EG Risk 32/100SSVC: 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
Severity61% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
12%
KEV
Not listed

Published

March 7, 2026

Last Modified

June 17, 2026

Advisory Details (1)

Auto-updated Aug 4, 2026
Patch available. Sources: github.
github Patch Available

DisallowedRawHtml extension bypass via whitespace in HTML tag names · Advisory · thephpleague/commonmark · GitHub

Affected: 2.8.1. The regex character class

https://github.com/thephpleague/commonmark/security/advisories/GHSA-4v6x-c7xx-hw9f

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
php-league-commonmark1.5.7-2 ... 2.8.3-1 (38 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
php-league-commonmark2.3.9-12.3.9-1+deb12u1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
php-league-commonmark2.7.0-12.7.0-1+deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
php-league-commonmark2.7.0-1, 2.7.1-1, 2.7.1-2, 2.8.0-12.8.1-1—
Packagist(1)
PackageVulnerable rangeFixed inDependents
league/commonmark2.0.0 ... 2.8.0 (40 versions)2.8.1—

Weakness Classification(1)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 7× in last 7d / 30× 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. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-17 19:30 UTCEPSS rescore
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-13 16:47 UTCEPSS rescore
  7. 2026-09-12 15:01 UTCEPSS rescore
  8. 2026-09-11 14:52 UTCEPSS rescore
  9. 2026-09-10 09:34 UTCEPSS rescore
  10. 2026-09-08 22:00 UTCEPSS rescore
  11. 2026-09-07 16:01 UTCEPSS rescore
  12. 2026-09-06 13:47 UTCEPSS rescore
  13. 2026-09-06 13:47 UTCEPSS rescore
  14. 2026-09-04 05:06 UTCEPSS rescore
  15. 2026-09-02 23:29 UTCOSV refresh
  16. 2026-09-02 14:11 UTCEPSS rescore
  17. 2026-09-01 13:53 UTCEPSS rescore
  18. 2026-09-01 04:39 UTCEPSS rescore
  19. 2026-09-01 04:39 UTCEPSS rescore
  20. 2026-08-30 19:17 UTCEPSS rescore
  21. 2026-08-30 01:22 UTCEPSS rescore
  22. 2026-08-28 21:41 UTCEPSS rescore
  23. 2026-08-27 14:25 UTCEPSS rescore
  24. 2026-08-26 14:46 UTCEPSS rescore
  25. 2026-08-25 13:49 UTCEPSS rescore
Show 46 more
  1. 2026-08-24 14:17 UTCEPSS rescore
  2. 2026-08-23 00:19 UTCEPSS rescore
  3. 2026-08-21 23:49 UTCEPSS rescore
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-19 17:03 UTCEPSS rescore
  7. 2026-08-18 13:48 UTCEPSS rescore
  8. 2026-08-17 13:47 UTCEPSS rescore
  9. 2026-08-16 14:56 UTCEPSS rescore
  10. 2026-08-16 12:17 UTCEG score recompute
  11. 2026-08-16 12:17 UTCVendor advisory
  12. 2026-08-16 02:14 UTCEPSS rescore
  13. 2026-08-15 01:30 UTCEPSS rescore
  14. 2026-08-14 08:12 UTCEG score recompute
  15. 2026-08-14 08:12 UTCVendor advisory
  16. 2026-08-13 22:00 UTCEPSS rescore
  17. 2026-08-12 23:41 UTCEG score recompute
  18. 2026-08-12 23:41 UTCVendor advisory
  19. 2026-08-12 13:50 UTCEPSS rescore
  20. 2026-08-11 05:56 UTCEG score recompute
  21. 2026-08-11 05:56 UTCVendor advisory
  22. 2026-08-11 00:00 UTCEPSS rescore
  23. 2026-08-10 07:00 UTCEG score recompute
  24. 2026-08-10 07:00 UTCVendor advisory
  25. 2026-08-09 13:46 UTCEPSS rescore
  26. 2026-08-09 07:52 UTCEG score recompute
  27. 2026-08-09 07:52 UTCVendor advisory
  28. 2026-08-08 16:37 UTCEPSS rescore
  29. 2026-08-07 19:18 UTCEG score recompute
  30. 2026-08-07 19:18 UTCVendor advisory
  31. 2026-08-06 13:46 UTCEPSS rescore
  32. 2026-08-06 02:20 UTCEG score recompute
  33. 2026-08-06 02:20 UTCVendor advisory
  34. 2026-08-05 19:17 UTCEPSS rescore
  35. 2026-08-04 15:10 UTCEPSS rescore
  36. 2026-08-04 01:45 UTCEG score recompute
  37. 2026-08-04 01:45 UTCVendor advisory
  38. 2026-08-03 10:36 UTCEPSS rescore
  39. 2026-08-02 18:32 UTCEG score recompute
  40. 2026-08-02 18:32 UTCVendor advisory
  41. 2026-08-02 02:26 UTCEPSS rescore
  42. 2026-08-01 04:16 UTCEPSS rescore
  43. 2026-07-30 16:27 UTCEPSS rescore
  44. 2026-07-30 01:30 UTCEPSS rescore
  45. 2026-07-28 15:36 UTCEPSS rescore
  46. 2026-07-27 13:37 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-30838?
CVE-2026-30838 is a medium vulnerability published on March 7, 2026. league/commonmark is a PHP Markdown parser. Prior to version 2.8.1, the DisallowedRawHtml extension can be bypassed by inserting a newline, tab, or other ASCII whitespace character between a disallowed HTML tag name and the closing >. For example, <script\n> would pass through unfiltered and be…
When was CVE-2026-30838 disclosed?
CVE-2026-30838 was first published in the National Vulnerability Database on March 7, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-30838 actively exploited?
CVE-2026-30838 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 87.6% of all scored CVEs.
What is the CVSS score of CVE-2026-30838?
CVE-2026-30838 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-30838?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-30838, 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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