CVE-2026-25210

HIGHNVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.8 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 91% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.8Exploit: None knownExposed: 0

A fix is available — apply it.

In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: 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
Severity78% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
10%
KEV
Not listed

Published

January 30, 2026

Last Modified

June 17, 2026

Advisory Details (3)

Auto-updated Aug 2, 2026
Upstream fix merged — awaiting tagged release. Sources: github_pr.
generic

SSA-253495

https://cert-portal.siemens.com/productcert/html/ssa-253495.html
github_pr

[CVE-2026-25210] Improve determination of buffer size `bufSize` in function `doContent`

Fix merged in libexpat/libexpat PR #1075 on 2025-10-03 — awaiting tagged release

https://github.com/libexpat/libexpat/pull/1075/commits/9c2d990389e6abe2e44527eeaa8b39f16fe859c7
github_pr

[CVE-2026-25210] Improve determination of buffer size `bufSize` in function `doContent`

Fix merged in libexpat/libexpat PR #1075 on 2025-10-03 — awaiting tagged release

https://github.com/libexpat/libexpat/pull/1075

Vendor Advisories for CVE-2026-25210(1)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibexpat1-dev (2.6.1-2ubuntu0.4) @ noble2026-06-08ubuntu
ubuntulibxmltok1-dev (1.2-4ubuntu0.20.04.1~esm6) @ focal2026-06-08ubuntu
ubuntulibexpat1-dev (2.4.7-1ubuntu0.7) @ jammy2026-06-08ubuntu

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

(9 across 9 ecosystems)
Alpine:v3.20(1)
PackageVulnerable rangeFixed inDependents
expat—2.7.4-r0—
Alpine:v3.21(1)
PackageVulnerable rangeFixed inDependents
expat—2.7.4-r0—
Alpine:v3.22(1)
PackageVulnerable rangeFixed inDependents
expat—2.7.4-r0—
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
expat—2.7.4-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
expat—2.7.4-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
expat2.2.10-2 ... 2.8.2-1~deb13u1 (47 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
expat2.5.0-1 ... 2.8.4-1 (29 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
expat2.7.1-2 ... 2.8.1-1 (9 versions)2.8.2-1~deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
expat2.7.1-2, 2.7.2-1, 2.7.3-1, 2.7.3-22.7.4-1—

Weakness Classification(1)

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

All Vendor Advisories

(3)

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 5× in last 7d / 24× 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 179 total refreshes for this CVE.

  1. 2026-09-20 20:15 UTCEPSS rescore
  2. 2026-09-19 17:00 UTCOSV refresh
  3. 2026-09-18 19:27 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 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 14:11 UTCEPSS rescore
  16. 2026-09-01 13:53 UTCEPSS rescore
  17. 2026-08-31 20:05 UTCOSV refresh
  18. 2026-08-30 19:17 UTCEPSS rescore
  19. 2026-08-30 01:22 UTCEPSS rescore
  20. 2026-08-28 21:41 UTCEPSS rescore
  21. 2026-08-27 14:25 UTCEPSS rescore
  22. 2026-08-26 14:46 UTCEPSS rescore
  23. 2026-08-25 13:48 UTCEPSS rescore
  24. 2026-08-23 00:19 UTCEPSS rescore
  25. 2026-08-21 23:49 UTCEPSS rescore
Show 75 more
  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. 2026-08-17 13:47 UTCEPSS rescore
  5. 2026-08-16 14:56 UTCEPSS rescore
  6. 2026-08-16 02:14 UTCEPSS rescore
  7. 2026-08-15 01:30 UTCEPSS rescore
  8. 2026-08-14 23:03 UTCVendor advisory
  9. 2026-08-14 23:03 UTCGHSA enrichment
  10. 2026-08-14 11:52 UTCEG score recompute
  11. 2026-08-14 11:52 UTCVendor advisory
  12. 2026-08-14 11:52 UTCGHSA enrichment
  13. 2026-08-13 22:00 UTCEPSS rescore
  14. 2026-08-13 03:59 UTCEG score recompute
  15. 2026-08-13 03:59 UTCVendor advisory
  16. 2026-08-13 03:59 UTCGHSA enrichment
  17. 2026-08-12 13:50 UTCEPSS rescore
  18. 2026-08-11 13:42 UTCEPSS rescore
  19. 2026-08-11 00:00 UTCEPSS rescore
  20. 2026-08-10 03:21 UTCVendor advisory
  21. 2026-08-10 03:21 UTCGHSA enrichment
  22. 2026-08-09 16:24 UTCEG score recompute
  23. 2026-08-09 16:24 UTCVendor advisory
  24. 2026-08-09 16:24 UTCGHSA enrichment
  25. 2026-08-09 13:46 UTCEPSS rescore
  26. 2026-08-08 16:37 UTCEPSS rescore
  27. 2026-08-08 10:06 UTCVendor advisory
  28. 2026-08-08 10:06 UTCGHSA enrichment
  29. 2026-08-07 23:10 UTCEG score recompute
  30. 2026-08-07 23:10 UTCVendor advisory
  31. 2026-08-07 23:10 UTCGHSA enrichment
  32. 2026-08-06 13:46 UTCEPSS rescore
  33. 2026-08-06 04:41 UTCEG score recompute
  34. 2026-08-06 04:41 UTCVendor advisory
  35. 2026-08-06 04:41 UTCGHSA enrichment
  36. 2026-08-05 19:17 UTCEPSS rescore
  37. 2026-08-04 15:10 UTCEPSS rescore
  38. 2026-08-03 10:36 UTCEPSS rescore
  39. 2026-08-02 21:51 UTCEG score recompute
  40. 2026-08-02 21:51 UTCVendor advisory
  41. 2026-08-02 21:51 UTCGHSA enrichment
  42. 2026-08-02 02:26 UTCEPSS rescore
  43. 2026-08-01 04:16 UTCEPSS rescore
  44. 2026-07-31 04:46 UTCOSV refresh
  45. 2026-07-30 16:27 UTCEPSS rescore
  46. 2026-07-30 01:30 UTCEPSS rescore
  47. 2026-07-27 14:13 UTCEPSS rescore
  48. 2026-07-26 14:54 UTCEPSS rescore
  49. 2026-07-26 14:54 UTCEPSS rescore
  50. 2026-07-25 14:17 UTCEPSS rescore
  51. 2026-07-25 14:17 UTCEPSS rescore
  52. 2026-07-24 14:17 UTCEPSS rescore
  53. 2026-07-23 14:18 UTCEPSS rescore
  54. 2026-07-23 14:18 UTCEPSS rescore
  55. 2026-07-23 03:07 UTCEG score recompute▲ 0.90
  56. 2026-07-22 14:08 UTCEPSS rescore
  57. 2026-07-21 15:24 UTCEPSS rescore
  58. 2026-07-21 15:24 UTCEPSS rescore
  59. 2026-07-20 17:08 UTCEPSS rescore
  60. 2026-07-19 14:31 UTCEPSS rescore
  61. 2026-07-19 14:31 UTCEPSS rescore
  62. 2026-07-19 02:29 UTCEPSS rescore
  63. 2026-07-19 02:28 UTCEPSS rescore
  64. 2026-07-18 10:04 UTCEPSS rescore
  65. 2026-07-18 10:04 UTCEPSS rescore
  66. 2026-07-16 17:03 UTCEPSS rescore
  67. 2026-07-16 17:03 UTCEPSS rescore
  68. 2026-07-15 16:57 UTCEPSS rescore
  69. 2026-07-15 16:57 UTCEPSS rescore
  70. 2026-07-15 02:00 UTCEPSS rescore
  71. 2026-07-15 02:00 UTCEPSS rescore
  72. 2026-07-13 22:30 UTCEPSS rescore
  73. 2026-07-13 12:38 UTCOSV refresh
  74. 2026-07-13 06:13 UTCEPSS rescore
  75. 2026-07-13 06:13 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-25210?
CVE-2026-25210 is a high vulnerability published on January 30, 2026. In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation.
When was CVE-2026-25210 disclosed?
CVE-2026-25210 was first published in the National Vulnerability Database on January 30, 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-2026-25210 actively exploited?
CVE-2026-25210 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 89.8% of all scored CVEs.
What is the CVSS score of CVE-2026-25210?
CVE-2026-25210 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2026-25210?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-25210, 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-2026-25210

Explore →

Is Your Infrastructure Affected by CVE-2026-25210?

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

Start Free Scan →Browse All CVEs