CVE-2026-41401

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-05-26. NVD baseline CVSS 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 6.5Exploit: NoneExposed: 0

A fix is available — apply it.

libyang before 5.2.6 contains a heap use-after-free write vulnerability in lyd_parser_set_data_flags that incorrectly updates metadata list pointers when freeing non-head default metadata entries. Attackers can trigger this vulnerability by submitting crafted YANG XML documents with specific metadata attributes to applications parsing untrusted XML data, causing process crashes or potential code execution.

CVSS v3
6.5
EG Score
6.5(medium)
EPSS
40.7%
KEV
Not listed

Published

May 26, 2026

Last Modified

May 26, 2026

Advisory Details (4)

Auto-updated Jun 13, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
generic🟡 PoC Available

ANT-2026-TZQ1KH7E · libyang

https://red.anthropic.com/2026/cvd/findings/ANT-2026-TZQ1KH7E
github Patch Available🟡 PoC Available

Heap Use-After-Free write in libyang XML metadata parsing (lyd_parse_data_mem / lyd_parse_mem_xml) · Advisory · CESNET/libyang · GitHub

https://github.com/CESNET/libyang/security/advisories/GHSA-9f49-8x56-jmjc
generic

libyang - Heap Use-After-Free Write in XML Metadata Parsing | Advisories | VulnCheck

https://www.vulncheck.com/advisories/libyang-heap-use-after-free-write-in-xml-metadata-parsing
github_commit Patch Available

commit 6b5ed47ee674 (CESNET/libyang)

Patch available: CESNET/libyang v5.4.9 (contains commit 6b5ed47ee674)

https://github.com/CESNET/libyang/commit/6b5ed47ee674fbe86b31bbebc4ff26889aeff38c

Vendor Advisories for CVE-2026-41401(2)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibyang3-tools (3.13.6-1ubuntu0.1) @ resolute2026-07-01ubuntu

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.

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 9× in last 7d / 48× 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 122 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-41401?
CVE-2026-41401 is a medium vulnerability published on May 26, 2026. libyang before 5.2.6 contains a heap use-after-free write vulnerability in lydparsersetdataflags that incorrectly updates metadata list pointers when freeing non-head default metadata entries. Attackers can trigger this vulnerability by submitting crafted YANG XML documents with specific metadata…
When was CVE-2026-41401 disclosed?
CVE-2026-41401 was first published in the National Vulnerability Database on May 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-41401 actively exploited?
CVE-2026-41401 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 40.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-41401?
CVE-2026-41401 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-41401?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-41401, 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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