CVE-2026-26278

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: 0.8%, top 44% 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
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: None knownExposed: 0

A fix is available — apply it.

fast-xml-parser allows users to validate XML, parse XML to JS object, or build XML from JS object without C/C++ based libraries and no callback. In versions 4.1.3 through 5.3.5, the XML parser can be forced to do an unlimited amount of entity expansion. With a very small XML input, it’s possible to make the parser spend seconds or even minutes processing a single request, effectively freezing the application. Version 5.3.6 fixes the issue. As a workaround, avoid using DOCTYPE parsing by processEntities: false option.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
57%
KEV
Not listed

Published

February 19, 2026

Last Modified

September 10, 2026

Advisory Details (10)

Auto-updated Jul 3, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github, redhat.
redhat Patch Available
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26278.json
redhat

2441120 – (CVE-2026-26278) CVE-2026-26278 fast-xml-parser: fast-xml-parser: Denial of Service via unlimited XML entity expansion

https://bugzilla.redhat.com/show_bug.cgi?id=2441120
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-26278
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:7128
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:7110
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:6802
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:6174
github Patch Available🟡 PoC Available

DoS through entity expansion in DOCTYPE (no expansion limit) · Advisory · NaturalIntelligence/fast-xml-parser · GitHub

https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-jmr7-xgp7-cmfj
github_release Patch Available

Entity security and performance

Patch available: NaturalIntelligence/fast-xml-parser v5.3.6

https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.3.6
github_commit Patch Available

commit 910dae5be2de (NaturalIntelligence/fast-xml-parser)

Patch available: NaturalIntelligence/fast-xml-parser v5.3.6 (contains commit 910dae5be2de)

https://github.com/NaturalIntelligence/fast-xml-parser/commit/910dae5be2de2955e968558fadf6e8f74f117a77

Vendor Advisories for CVE-2026-26278(8)

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

Patch Availability(8)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatsatellite/iop-host-inventory-frontend-rhel9:17859227642026-08-06redhat
redhatodf4/rook-ceph-rhel9-operator:17836853752026-07-20redhat
redhatodf4/rook-ceph-rhel9-operator:17836775332026-07-20redhat
redhatodf4/rook-ceph-rhel9-operator:17836692192026-07-16redhat
redhatadvanced-cluster-security/rhacs-main-rhel8:17755941192026-04-08redhat
redhatadvanced-cluster-security/rhacs-main-rhel8:17755942842026-04-08redhat
redhatrhdh/rhdh-hub-rhel9:17751406472026-04-07redhat
redhatrhdh/rhdh-hub-rhel9:17745456052026-03-30redhat

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 rangeFixed inDependents
node-webfont11.4.0+dfsg2+~cs35.7.26-10 ... 11.4.0+dfsg2+~cs35.7.26-9 (14 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
node-webfont11.4.0+dfsg2+~cs35.7.26-13 ... 11.4.0+dfsg2+~cs35.7.26-21 (8 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
node-webfont11.4.0+dfsg2+~cs35.7.26-13 ... 11.4.0+dfsg2+~cs35.7.26-21 (8 versions)——
npm(1)
PackageVulnerable rangeFixed inDependents
fast-xml-parser—5.3.6—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 40× 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 151 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-26278?
CVE-2026-26278 is a high vulnerability published on February 19, 2026. fast-xml-parser allows users to validate XML, parse XML to JS object, or build XML from JS object without C/C++ based libraries and no callback. In versions 4.1.3 through 5.3.5, the XML parser can be forced to do an unlimited amount of entity expansion. With a very small XML input, it’s possible to…
When was CVE-2026-26278 disclosed?
CVE-2026-26278 was first published in the National Vulnerability Database on February 19, 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-2026-26278 actively exploited?
CVE-2026-26278 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 43.2% of all scored CVEs.
What is the CVSS score of CVE-2026-26278?
CVE-2026-26278 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-26278?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-26278, 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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