CVE-2026-26824

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory published 2026-06-03. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this weekElevated
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

libxls through version 1.6.3 contains a use of uninitialized memory vulnerability in the OLE container parser. Memory allocated for the Master Sector Allocation Table (MSAT) in read_MSAT() is not fully initialized before being consumed by ole2_validate_sector_chain(), which may result in application crashes or potential information disclosure when processing a crafted XLS file

CVSS v3
6.5
EG Score
6.5(medium)
EPSS
13.5%
KEV
Not listed

Published

June 3, 2026

Last Modified

June 4, 2026

Advisory Details (1)

Auto-updated Jun 12, 2026
No patch confirmed yet.
generic

Use of uninitialized memory in libxls OLE sector chain validation · Issue #155 · libxls/libxls · GitHub

https://github.com/libxls/libxls/issues/155

Vendor Advisories for CVE-2026-26824(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 83× 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 124 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-26824?
CVE-2026-26824 is a medium vulnerability published on June 3, 2026. libxls through version 1.6.3 contains a use of uninitialized memory vulnerability in the OLE container parser. Memory allocated for the Master Sector Allocation Table (MSAT) in readMSAT() is not fully initialized before being consumed by ole2validatesectorchain(), which may result in application…
When was CVE-2026-26824 disclosed?
CVE-2026-26824 was first published in the National Vulnerability Database on June 3, 2026, with the most recent update on June 4, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-26824 actively exploited?
CVE-2026-26824 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 13.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-26824?
CVE-2026-26824 has a CVSS v3.1 base score of 6.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-26824?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-26824, 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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