CVE-2026-67422

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6% (47th percentile of EPSS-scored CVEs). 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
Trending — 3 sources updated this weekElevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 7.5Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

pymdown-extensions is a collection of extensions for the Python Markdown library. In versions up to and including 11.0, four inline processors (caret, tilde, betterem, and magiclink) use regular expressions whose content groups can partition a run of delimiter characters in exponentially many ways, causing catastrophic backtracking. As a result, a single untrusted Markdown line under 50 bytes rendered with markdown.markdown() in each extension's default configuration drives the rendering thread into unbounded CPU usage that grows exponentially with input length, enabling an unauthenticated remote attacker who can submit Markdown to cause denial of service. The exposure is concrete for web applications that render user-supplied Markdown (comments, wikis, issue bodies, live preview), including any app using pymdownx.extra which bundles the vulnerable betterem default, as well as hosted docs/CI systems that build untrusted Markdown. The issue has been fixed in version 11.0.1.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100CISA SSVC

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
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.6%
EPSS %ILE
47th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 6, 2026

Last Modified

September 10, 2026

Advisory Details (2)

Auto-updated Aug 6, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit.
github_commit Patch Available

commit c68498598d7b (facelessuser/pymdown-extensions)

Patch available: facelessuser/pymdown-extensions 11.0.1 (contains commit c68498598d7b)

https://github.com/facelessuser/pymdown-extensions/commit/c68498598d7b13011bb4571350b6e3612a4ce44b
github Patch Available🟡 PoC Available

pymdown-extensions: exponential-backtracking ReDoS in caret, tilde, betterem, and magiclink inline processors · Advisory · facelessuser/pymdown-extensions · GitHub

Affected: 10.16.1): different extensions, different regexes, and a

https://github.com/facelessuser/pymdown-extensions/security/advisories/GHSA-gm37-52c6-37mw

Vendor Advisories for CVE-2026-67422(3)

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

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrhdh/rhdh-hub-rhel9:17895542852026-09-21redhat
redhatansible-automation-platform/bootc-automation-portal-rhel9:17889435312026-09-09redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(4 across 4 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
pymdown-extensions10.11.2-1 ... 9.5-5 (14 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
pymdown-extensions10.13-1 ... 11.0.1-1 (8 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
pymdown-extensions10.13-1 ... 10.19.1-3 (6 versions)
  • every version up to 11.0.1-1: fixed in 11.0.1-1
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
pymdown-extensions1.0.0 ... 9.9.2 (119 versions)
  • every version up to 11.0.1: fixed in 11.0.1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 18× in last 7d / 78× 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 131 total refreshes for this CVE.

  1. 2026-10-04 23:22 UTCEPSS rescore
  2. 2026-10-04 23:21 UTCVendor advisory
  3. 2026-10-04 05:48 UTCEG score recompute
  4. 2026-10-04 05:48 UTCVendor advisory
  5. 2026-10-03 14:26 UTCEPSS rescore
  6. 2026-10-03 01:03 UTCEG score recompute
  7. 2026-10-03 01:03 UTCVendor advisory
  8. 2026-10-02 17:56 UTCEPSS rescore
  9. 2026-10-02 09:37 UTCEG score recompute
  10. 2026-10-02 09:37 UTCVendor advisory
  11. 2026-10-01 19:50 UTCEPSS rescore
  12. 2026-10-01 12:11 UTCVendor advisory
  13. 2026-09-30 23:00 UTCEG score recompute
  14. 2026-09-30 23:00 UTCVendor advisory
  15. 2026-09-30 15:03 UTCEPSS rescore
  16. 2026-09-29 05:52 UTCEG score recompute
  17. 2026-09-29 05:52 UTCVendor advisory
  18. 2026-09-28 13:52 UTCEPSS rescore
  19. 2026-09-28 06:35 UTCVendor advisory
  20. 2026-09-27 17:28 UTCEG score recompute
  21. 2026-09-27 17:28 UTCVendor advisory
  22. 2026-09-27 13:48 UTCEPSS rescore
  23. 2026-09-26 15:59 UTCEPSS rescore
  24. 2026-09-25 04:20 UTCEG score recompute
  25. 2026-09-25 04:20 UTCVendor advisory
Show 75 more
  1. 2026-09-24 10:25 UTCVendor advisory
  2. 2026-09-23 21:17 UTCEG score recompute
  3. 2026-09-23 21:17 UTCVendor advisory
  4. 2026-09-23 17:54 UTCEPSS rescore
  5. 2026-09-23 04:14 UTCEG score recompute
  6. 2026-09-23 04:14 UTCVendor advisory
  7. 2026-09-22 15:06 UTCVendor advisory
  8. 2026-09-22 01:53 UTCEG score recompute
  9. 2026-09-22 01:53 UTCVendor advisory
  10. 2026-09-21 12:45 UTCEG score recompute
  11. 2026-09-21 12:45 UTCVendor advisory
  12. 2026-09-20 20:16 UTCEPSS rescore
  13. 2026-09-20 10:57 UTCVendor advisory
  14. 2026-09-19 21:25 UTCEG score recompute
  15. 2026-09-19 21:25 UTCVendor advisory
  16. 2026-09-19 07:28 UTCEG score recompute
  17. 2026-09-19 07:28 UTCVendor advisory
  18. 2026-09-18 19:28 UTCEPSS rescore
  19. 2026-09-18 17:35 UTCVendor advisory
  20. 2026-09-18 04:21 UTCEG score recompute
  21. 2026-09-18 04:21 UTCVendor advisory
  22. 2026-09-17 15:13 UTCVendor advisory
  23. 2026-09-17 00:57 UTCEG score recompute
  24. 2026-09-17 00:57 UTCVendor advisory
  25. 2026-09-16 14:08 UTCEPSS rescore
  26. 2026-09-16 05:15 UTCEPSS rescore
  27. 2026-09-16 03:36 UTCVendor advisory
  28. 2026-09-15 14:24 UTCEG score recompute
  29. 2026-09-15 14:24 UTCVendor advisory
  30. 2026-09-15 01:08 UTCVendor advisory
  31. 2026-09-14 04:36 UTCEG score recompute
  32. 2026-09-14 04:36 UTCVendor advisory
  33. 2026-09-13 15:29 UTCVendor advisory
  34. 2026-09-13 02:21 UTCEG score recompute
  35. 2026-09-13 02:21 UTCVendor advisory
  36. 2026-09-12 13:13 UTCVendor advisory
  37. 2026-09-12 00:05 UTCEG score recompute
  38. 2026-09-12 00:05 UTCVendor advisory
  39. 2026-09-11 14:53 UTCEPSS rescore
  40. 2026-09-11 09:58 UTCEG score recompute
  41. 2026-09-11 09:58 UTCVendor advisory
  42. 2026-09-11 09:37 UTCEPSS rescore
  43. 2026-09-10 20:43 UTCEG score recompute
  44. 2026-09-10 20:43 UTCVendor advisory
  45. 2026-09-10 08:45 UTCVendor advisory
  46. 2026-09-09 06:06 UTCEG score recompute
  47. 2026-09-08 22:01 UTCEPSS rescore
  48. 2026-09-07 17:51 UTCEG score recompute
  49. 2026-09-07 16:01 UTCEPSS rescore
  50. 2026-09-06 18:57 UTCEG score recompute
  51. 2026-09-06 13:47 UTCEPSS rescore
  52. 2026-09-05 16:40 UTCEG score recompute
  53. 2026-09-05 15:31 UTCEPSS rescore
  54. 2026-09-05 03:28 UTCEG score recompute
  55. 2026-09-04 09:11 UTCEG score recompute
  56. 2026-09-04 05:07 UTCEPSS rescore
  57. 2026-09-03 06:12 UTCEG score recompute
  58. 2026-09-02 14:12 UTCEPSS rescore
  59. 2026-09-01 17:56 UTCEG score recompute
  60. 2026-09-01 13:54 UTCEPSS rescore
  61. 2026-09-01 04:40 UTCEPSS rescore
  62. 2026-08-31 02:02 UTCEG score recompute
  63. 2026-08-30 19:17 UTCEPSS rescore
  64. 2026-08-30 12:54 UTCEG score recompute
  65. 2026-08-30 01:22 UTCEPSS rescore
  66. 2026-08-29 10:34 UTCEG score recompute
  67. 2026-08-28 21:42 UTCEPSS rescore
  68. 2026-08-28 01:34 UTCEG score recompute
  69. 2026-08-26 23:20 UTCEG score recompute
  70. 2026-08-26 14:47 UTCEPSS rescore
  71. 2026-08-25 20:43 UTCEG score recompute
  72. 2026-08-25 13:49 UTCEPSS rescore
  73. 2026-08-24 18:27 UTCEG score recompute
  74. 2026-08-23 03:00 UTCEG score recompute
  75. 2026-08-23 00:19 UTCEPSS rescore

Related CVEs(same product + same vendor + same CWE)

Same product

4 shown

Debian:12:pymdown-extensions · Debian:13:pymdown-extensions

Frequently asked(5)

What is CVE-2026-67422?
CVE-2026-67422 is a high vulnerability published on August 6, 2026. pymdown-extensions is a collection of extensions for the Python Markdown library. In versions up to and including 11.0, four inline processors (caret, tilde, betterem, and magiclink) use regular expressions whose content groups can partition a run of delimiter characters in exponentially many ways,…
When was CVE-2026-67422 disclosed?
CVE-2026-67422 was first published on August 6, 2026, with the most recent update on September 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-67422 actively exploited?
CVE-2026-67422 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (47th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-67422?
CVE-2026-67422 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-67422?
A fix for CVE-2026-67422 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-67422 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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