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: 1.0%CVSS: 7.5Exploit: None knownExposed services: Not assessed

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
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100

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%
EPSS PROB
1.0%
EPSS %ILE
60th
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 / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
node-webfont11.4.0+dfsg2+~cs35.7.26-10 ... 11.4.0+dfsg2+~cs35.7.26-9 (14 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
node-webfont11.4.0+dfsg2+~cs35.7.26-13 ... 11.4.0+dfsg2+~cs35.7.26-21 (8 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
node-webfont11.4.0+dfsg2+~cs35.7.26-13 ... 11.4.0+dfsg2+~cs35.7.26-21 (8 versions)
  • every version on: no fix on record
—
npm(1)
PackageVulnerable rangeFix by version rangeDependents
fast-xml-parser—
  • 4.1.3 up to 4.5.4: fixed in 4.5.4
  • 5.0.0 up to 5.3.6: fixed in 5.3.6
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 6× 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.

Showing the most recent 100 of 162 total refreshes for this CVE.

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

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

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 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 1.0% probability of exploitation in the next 30 days (60th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-26278?
CVE-2026-26278 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-2026-26278?
A fix for CVE-2026-26278 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-26278 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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