CVE-2026-63633

HIGHPre-NVD 7.77.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 61% 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, secondary
Trending — Patch released this weekElevated
7.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.7Exploit: Elevated riskExposed: 0

A fix is available — apply it.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, freerdp_dsp_decode_opus in libfreerdp/codec/dsp.c calls Stream_EnsureRemainingCapacity on context->common.buffer even though opus_decode writes decoded PCM into the caller-supplied out stream. A malicious RDP server that negotiates WAVE_FORMAT_OPUS with a client built with WITH_OPUS enabled and WITH_DSP_FFMPEG disabled can make libopus write a large decoded frame beyond the 4096-byte StreamPool_Take destination used by channels/rdpsnd/client/rdpsnd_main.c. This can corrupt the client heap, crash the client, and may permit code execution. This issue is fixed in version 3.28.0.

CVSS v3
7.7
EG Score
7.7(medium)
EG Risk
51(Track*)
EG Risk 51/100SSVC: 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
Severity77% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Watch closely — could escalate to Attend.
EPSS PROB
0%
EPSS %ILE
39%
KEV
Not listed

Published

August 19, 2026

Last Modified

September 9, 2026

Advisory Details (4)

Auto-updated Aug 19, 2026
🔬 Proof of concept available. Patch available. Sources: github_pr, github_release, github, github_commit.
github Patch Available🟡 PoC Available

Heap buffer overflow in FreeRDP Opus audio decode (`freerdp_dsp_decode_opus` resizes the wrong stream) — server→client · Advisory · FreeRDP/FreeRDP · GitHub

Affected: 3.24.0) — that fix did not touch

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-72j9-356v-88xq
github_release Patch Available

3.28.0

Patch available: FreeRDP/FreeRDP 3.28.0

https://github.com/FreeRDP/FreeRDP/releases/tag/3.28.0
github_pr

Range checks

Fix merged in FreeRDP/FreeRDP PR #12993 on 2026-07-02 — awaiting tagged release

https://github.com/FreeRDP/FreeRDP/pull/12993
github_commit

commit 0ed1f95d3691 (FreeRDP/FreeRDP)

Fix landed in FreeRDP/FreeRDP commit 0ed1f95d3691 — awaiting tagged release

https://github.com/FreeRDP/FreeRDP/commit/0ed1f95d36913581cf31124f94eb5843d4263eae

Vendor Advisories for CVE-2026-63633(1)

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

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatfreerdp-2:3.10.3-3.el10_0.162026-09-17redhat
redhatfreerdp-2:3.10.3-12.el10_2.102026-08-31redhat

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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
freerdp22.10.0+dfsg1-1 ... 2.11.7+dfsg1-6~deb12u1 (13 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
freerdp33.15.0+dfsg-2.1 ... 3.31.0+dfsg-1 (44 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
freerdp33.15.0+dfsg-2.1 ... 3.27.1+dfsg-1 (35 versions)3.28.0+dfsg-1—

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 24× in last 7d / 88× 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. 2026-09-19 10:14 UTCVendor advisory
  2. 2026-09-18 21:44 UTCEG score recompute
  3. 2026-09-18 21:44 UTCVendor advisory
  4. 2026-09-18 19:28 UTCEPSS rescore
  5. 2026-09-18 09:13 UTCVendor advisory
  6. 2026-09-17 21:29 UTCEG score recompute
  7. 2026-09-17 21:29 UTCVendor advisory
  8. 2026-09-17 07:50 UTCVendor advisory
  9. 2026-09-16 20:06 UTCEG score recompute
  10. 2026-09-16 20:06 UTCVendor advisory
  11. 2026-09-16 14:08 UTCEPSS rescore
  12. 2026-09-16 07:08 UTCEG score recompute
  13. 2026-09-16 07:08 UTCVendor advisory
  14. 2026-09-16 05:15 UTCEPSS rescore
  15. 2026-09-15 19:24 UTCVendor advisory
  16. 2026-09-15 07:40 UTCEG score recompute
  17. 2026-09-15 07:40 UTCVendor advisory
  18. 2026-09-14 19:56 UTCVendor advisory
  19. 2026-09-14 08:12 UTCVendor advisory
  20. 2026-09-13 20:28 UTCEG score recompute
  21. 2026-09-13 20:28 UTCVendor advisory
  22. 2026-09-13 08:44 UTCVendor advisory
  23. 2026-09-12 21:00 UTCEG score recompute
  24. 2026-09-12 21:00 UTCVendor advisory
  25. 2026-09-12 09:16 UTCVendor advisory
Show 66 more
  1. 2026-09-11 21:32 UTCEG score recompute
  2. 2026-09-11 21:32 UTCVendor advisory
  3. 2026-09-11 14:53 UTCEPSS rescore
  4. 2026-09-11 09:48 UTCEG score recompute
  5. 2026-09-11 09:48 UTCVendor advisory
  6. 2026-09-11 09:37 UTCEPSS rescore
  7. 2026-09-10 22:04 UTCVendor advisory
  8. 2026-09-10 10:20 UTCEG score recompute
  9. 2026-09-10 10:20 UTCVendor advisory
  10. 2026-09-09 22:36 UTCVendor advisory
  11. 2026-09-09 14:42 UTCVendor advisory
  12. 2026-09-09 02:34 UTCEG score recompute
  13. 2026-09-09 02:34 UTCVendor advisory
  14. 2026-09-08 22:01 UTCEPSS rescore
  15. 2026-09-08 07:43 UTCVendor advisory
  16. 2026-09-07 19:59 UTCEG score recompute
  17. 2026-09-07 19:59 UTCVendor advisory
  18. 2026-09-07 16:01 UTCEPSS rescore
  19. 2026-09-07 08:15 UTCVendor advisory
  20. 2026-09-06 20:12 UTCEG score recompute
  21. 2026-09-06 20:12 UTCVendor advisory
  22. 2026-09-06 13:47 UTCEPSS rescore
  23. 2026-09-06 08:27 UTCVendor advisory
  24. 2026-09-05 20:43 UTCEG score recompute
  25. 2026-09-05 20:43 UTCVendor advisory
  26. 2026-09-05 15:31 UTCEPSS rescore
  27. 2026-09-05 09:00 UTCVendor advisory
  28. 2026-09-04 21:15 UTCEG score recompute
  29. 2026-09-04 21:15 UTCVendor advisory
  30. 2026-09-04 08:29 UTCEG score recompute
  31. 2026-09-04 08:29 UTCVendor advisory
  32. 2026-09-04 05:07 UTCEPSS rescore
  33. 2026-09-03 20:44 UTCVendor advisory
  34. 2026-09-03 09:00 UTCVendor advisory
  35. 2026-09-02 21:17 UTCEG score recompute
  36. 2026-09-02 21:17 UTCVendor advisory
  37. 2026-09-02 14:12 UTCEPSS rescore
  38. 2026-09-02 07:43 UTCVendor advisory
  39. 2026-09-01 19:57 UTCEG score recompute
  40. 2026-09-01 19:57 UTCVendor advisory
  41. 2026-09-01 13:54 UTCEPSS rescore
  42. 2026-09-01 07:38 UTCEG score recompute
  43. 2026-09-01 04:40 UTCEPSS rescore
  44. 2026-08-31 06:37 UTCEG score recompute
  45. 2026-08-30 19:17 UTCEPSS rescore
  46. 2026-08-30 07:09 UTCEG score recompute
  47. 2026-08-30 01:22 UTCEPSS rescore
  48. 2026-08-29 07:23 UTCEG score recompute
  49. 2026-08-28 21:42 UTCEPSS rescore
  50. 2026-08-27 17:24 UTCEG score recompute
  51. 2026-08-27 14:25 UTCEPSS rescore
  52. 2026-08-27 01:30 UTCEG score recompute
  53. 2026-08-26 14:46 UTCEPSS rescore
  54. 2026-08-25 14:19 UTCEG score recompute
  55. 2026-08-25 13:49 UTCEPSS rescore
  56. 2026-08-24 14:51 UTCEG score recompute
  57. 2026-08-23 03:39 UTCEG score recompute
  58. 2026-08-23 00:19 UTCEPSS rescore
  59. 2026-08-22 04:12 UTCEG score recompute
  60. 2026-08-21 23:49 UTCEPSS rescore
  61. 2026-08-21 04:36 UTCEG score recompute
  62. 2026-08-21 04:02 UTCEG score recompute
  63. 2026-08-20 22:55 UTCEPSS rescore
  64. 2026-08-19 18:18 UTCEG score recompute
  65. 2026-08-19 18:13 UTCEG score recompute
  66. 2026-08-19 18:12 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-63633?
CVE-2026-63633 is a high vulnerability published on August 19, 2026. FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, freerdpdspdecodeopus in libfreerdp/codec/dsp.c calls StreamEnsureRemainingCapacity on context->common.buffer even though opusdecode writes decoded PCM into the caller-supplied out stream. A malicious RDP server that…
When was CVE-2026-63633 disclosed?
CVE-2026-63633 was first published in the National Vulnerability Database on August 19, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63633 actively exploited?
CVE-2026-63633 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 60.9% of all scored CVEs.
What is the CVSS score of CVE-2026-63633?
CVE-2026-63633 has a CVSS v3 base score of 7.7 (NVD).
How do I remediate CVE-2026-63633?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63633, 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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