CVE-2026-22858

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 70% 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: epss, nvd
Trending — 3 sources updated this weekElevated
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.1Exploit: NoneExposed: 0

A fix is available — apply it.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, global-buffer-overflow was observed in FreeRDP's Base64 decoding path. The root cause appears to be implementation-defined char signedness: on Arm/AArch64 builds, plain char is treated as unsigned, so the guard c <= 0 can be optimized into a simple c != 0 check. As a result, non-ASCII bytes (e.g., 0x80-0xFF) may bypass the intended range restriction and be used as an index into a global lookup table, causing out-of-bounds access. This vulnerability is fixed in 3.20.1.

CVSS v3
9.1
EG Score
9.1(medium)
EPSS
44.7%
KEV
Not listed

Published

January 14, 2026

Last Modified

July 15, 2026

Advisory Details (10)

Auto-updated Jun 30, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github, redhat.
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions.

https://access.redhat.com/errata/RHSA-2026:4437
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.2 Advanced Update Support.

https://access.redhat.com/errata/RHSA-2026:4433
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.0 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:4121
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.6 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:3975
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2026:3334
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:3068
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:3067
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:19033
github Patch Available🟡 PoC Available

Global-buffer-overflow in crypto_base64_decode · Advisory · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qmqf-m84q-x896
github_release Patch Available

3.20.1

Patch available: FreeRDP/FreeRDP 3.20.1

https://github.com/FreeRDP/FreeRDP/releases/tag/3.20.1

Vendor Advisories for CVE-2026-22858(14)

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

Patch Availability(15)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuwinpr3-utils (3.16.0+dfsg-2ubuntu0.3) @ questing2026-05-29ubuntu
redhatfreerdp-2:3.10.3-12.el10_2.22026-05-19redhat
redhatfreerdp-2:2.2.0-7.el8_6.22026-03-12redhat
redhatfreerdp-2:2.0.0-46.rc4.el8_2.72026-03-12redhat
redhatfreerdp-2:2.2.0-8.el8_42026-03-12redhat
redhatfreerdp-2:2.11.2-1.el9_4.22026-03-12redhat
redhatfreerdp-2:2.4.1-3.el9_0.12026-03-12redhat
redhatfreerdp-0:2.1.1-5.el7_9.22026-03-12redhat
redhatfreerdp-2:2.2.0-12.el8_8.22026-03-12redhat
redhatfreerdp-2:2.4.1-6.el9_2.32026-03-12redhat
redhatfreerdp-2:2.11.7-1.el9_6.22026-03-09redhat
redhatfreerdp-2:3.10.3-3.el10_0.22026-03-09redhat
redhatfreerdp-2:2.11.7-3.el8_102026-02-25redhat
redhatfreerdp-2:3.10.3-5.el10_1.22026-02-23redhat
redhatfreerdp-2:2.11.7-1.el9_7.22026-02-23redhat

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(3)

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 14× in last 7d / 53× 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.

  1. 2026-07-16 17:03 UTCEPSS rescore
  2. 2026-07-16 17:03 UTCEPSS rescore
  3. 2026-07-15 16:57 UTCEPSS rescore
  4. 2026-07-15 16:57 UTCEPSS rescore
  5. 2026-07-15 02:21 UTCNVD updateCVSS v3 → 9.1 · severity → CRITICAL
  6. 2026-07-15 02:06 UTCMITRE cvelistV5CVSS v3 → 7.4 · severity → HIGH
  7. 2026-07-15 02:00 UTCEPSS rescore
  8. 2026-07-15 02:00 UTCEPSS rescore
  9. 2026-07-13 22:30 UTCEPSS rescore
  10. 2026-07-13 06:13 UTCEPSS rescore
  11. 2026-07-13 06:13 UTCEPSS rescore
  12. 2026-07-12 05:46 UTCEPSS rescore
  13. 2026-07-12 05:46 UTCEPSS rescore
  14. 2026-07-11 08:27 UTCEPSS rescore
  15. 2026-07-09 19:10 UTCEPSS rescore
  16. 2026-07-08 15:15 UTCEPSS rescore
  17. 2026-07-08 15:15 UTCEPSS rescore
  18. 2026-07-07 13:46 UTCEPSS rescore
  19. 2026-07-06 16:27 UTCEPSS rescore
  20. 2026-07-06 16:27 UTCEPSS rescore
  21. 2026-07-06 05:32 UTCOSV refresh
  22. 2026-07-06 02:23 UTCEPSS rescore
  23. 2026-07-06 02:23 UTCEPSS rescore
  24. 2026-07-05 02:30 UTCEPSS rescore
  25. 2026-07-04 06:31 UTCEPSS rescore
Show 64 more
  1. 2026-07-04 06:31 UTCEPSS rescore
  2. 2026-07-01 15:06 UTCEPSS rescore
  3. 2026-07-01 15:06 UTCEPSS rescore
  4. 2026-06-30 23:22 UTCEPSS rescore
  5. 2026-06-30 23:22 UTCEPSS rescore
  6. 2026-06-29 14:06 UTCEPSS rescore
  7. 2026-06-28 14:07 UTCEPSS rescore
  8. 2026-06-28 14:07 UTCEPSS rescore
  9. 2026-06-28 04:56 UTCEPSS rescore
  10. 2026-06-28 04:56 UTCEPSS rescore
  11. 2026-06-27 03:08 UTCEPSS rescore
  12. 2026-06-25 13:49 UTCEPSS rescore
  13. 2026-06-25 13:49 UTCEPSS rescore
  14. 2026-06-24 14:05 UTCEPSS rescore
  15. 2026-06-24 14:05 UTCEPSS rescore
  16. 2026-06-23 21:33 UTCEPSS rescore
  17. 2026-06-23 21:32 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. 2026-06-21 01:59 UTCEPSS rescore
  24. 2026-06-19 19:25 UTCEPSS rescore
  25. 2026-06-19 19:25 UTCEPSS rescore
  26. 2026-06-18 17:52 UTCEPSS rescore
  27. 2026-06-17 17:53 UTCEPSS rescore
  28. 2026-06-17 17:05 UTCOSV refresh
  29. 2026-06-16 17:52 UTCEPSS rescore
  30. 2026-06-15 17:48 UTCEPSS rescore
  31. 2026-06-14 23:18 UTCEPSS rescore
  32. 2026-06-13 23:00 UTCEPSS rescore
  33. 2026-06-13 23:00 UTCEPSS rescore
  34. 2026-06-12 23:12 UTCEPSS rescore
  35. 2026-06-11 14:00 UTCEPSS rescore
  36. 2026-06-10 22:18 UTCEPSS rescore
  37. 2026-06-10 13:22 UTCEPSS rescore
  38. 2026-06-08 14:17 UTCEPSS rescore
  39. 2026-06-08 14:17 UTCEPSS rescore
  40. 2026-06-07 15:25 UTCEPSS rescore
  41. 2026-06-07 15:24 UTCEPSS rescore
  42. 2026-06-06 13:47 UTCEPSS rescore
  43. 2026-06-06 13:47 UTCEPSS rescore
  44. 2026-06-06 13:47 UTCEPSS rescore
  45. 2026-06-05 22:47 UTCEPSS rescore
  46. 2026-06-05 06:10 UTCEPSS rescore
  47. 2026-06-05 06:10 UTCEPSS rescore
  48. 2026-06-04 13:12 UTCEPSS rescore
  49. 2026-06-04 13:12 UTCEPSS rescore
  50. 2026-06-04 13:12 UTCEPSS rescore
  51. 2026-06-02 20:13 UTCEPSS rescore
  52. 2026-06-02 20:13 UTCEPSS rescore
  53. 2026-06-01 13:51 UTCEPSS rescore
  54. 2026-06-01 13:51 UTCEPSS rescore
  55. 2026-06-01 13:51 UTCEPSS rescore
  56. 2026-05-31 22:30 UTCEPSS rescore
  57. 2026-05-31 22:30 UTCEPSS rescore
  58. 2026-05-31 00:16 UTCEPSS rescore
  59. 2026-05-31 00:16 UTCEPSS rescore
  60. 2026-05-31 00:16 UTCEPSS rescore
  61. 2026-05-29 15:55 UTCEG score recompute
  62. 2026-05-29 15:55 UTCVendor advisory
  63. 2026-05-29 13:44 UTCEPSS rescore
  64. 2026-05-29 13:44 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-22858?
CVE-2026-22858 is a critical vulnerability published on January 14, 2026. FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, global-buffer-overflow was observed in FreeRDP's Base64 decoding path. The root cause appears to be implementation-defined char signedness: on Arm/AArch64 builds, plain char is treated as unsigned, so the guard c <= 0…
When was CVE-2026-22858 disclosed?
CVE-2026-22858 was first published in the National Vulnerability Database on January 14, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-22858 actively exploited?
CVE-2026-22858 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 44.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-22858?
CVE-2026-22858 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-22858?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-22858, 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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