CVE-2026-26278

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit probability: 0.8%, top 45% 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: cna:github_m, epss
Trending — 3 sources updated this week
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
55%
KEV
Not listed

Published

February 19, 2026

Last Modified

August 18, 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-rhel8:17755942842026-04-08redhat
redhatadvanced-cluster-security/rhacs-main-rhel8:17755941192026-04-08redhat
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 (13 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
node-webfont11.4.0+dfsg2+~cs35.7.26-13 ... 11.4.0+dfsg2+~cs35.7.26-20 (7 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
node-webfont11.4.0+dfsg2+~cs35.7.26-13 ... 11.4.0+dfsg2+~cs35.7.26-20 (7 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 14× in last 7d / 70× 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 112 total refreshes for this CVE.

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

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 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-2026-26278 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 44.9% 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-26278

Explore →

Is Your Infrastructure Affected by CVE-2026-26278?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs