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
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 6.5Exploit: Elevated riskExposed: 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)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
42%
KEV
Not listed

Published

May 26, 2026

Last Modified

July 24, 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) @ resolute2026-08-23ubuntu

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:11(1)
PackageVulnerable rangeFixed inDependents
libyang1.0.225-1.1 ... 6.1.4-1 (29 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
libyang22.1.148-0.1, 2.1.148-0.2, 2.1.30-2, 2.1.30-2.1, 2.1.30-2.1~exp1——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
libyang3.12.2-1 ... 6.1.4-1 (22 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
libyang3.12.2-1 ... 6.1.4-1 (22 versions)——

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 6× in last 7d / 67× 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 232 total refreshes for this CVE.

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

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, with the most recent update on July 24, 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 1% probability of exploitation in the next 30 days, which ranks it in the top 57.8% of all scored CVEs.
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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