CVE-2026-44421

HIGHPre-NVD 8.88.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This high-severity CVE scores 8.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.7% (52nd percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 3 sources updated this weekElevated
8.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 8.8Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client by sending crafted RDPGFX PDUs. The bug is in gdi_CacheToSurface: it validates a destination rectangle that is clamped to UINT16_MAX, but then performs the copy using the original cacheEntry->width/height. This can cause a large out-of-bounds heap write and may lead to client crashes or code execution. This bug is reachable from a malicious RDP server, but only when the client has RDPGFX enabled. This vulnerability is fixed in 3.26.0.

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
56
EG Risk 56/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.7%
EPSS %ILE
52nd
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track* at medium mission impactTrack at low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

May 29, 2026

Last Modified

July 27, 2026

Advisory Details (1)

Auto-updated Jun 2, 2026
Patch available. Sources: github.
GitHub advisoryMentions a patch (unverified)

FreeRDP RDPGFX CacheToSurface heap-buffer-overflow via clamped-rectangle validation bypass · Advisory · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff

Vendor Advisories for CVE-2026-44421(1)

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

Patch Availability(3)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntuwinpr3-utils (3.30.0+dfsg-0ubuntu0.26.04.1) @ resolute2026-10-17ubuntu
redhatfreerdp-2:3.10.3-3.el10_0.92026-07-27redhat
redhatfreerdp-2:3.10.3-12.el10_2.62026-07-07redhat

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 rangeFix by version rangeDependents
freerdp22.10.0+dfsg1-1 ... 2.9.0+dfsg1-1~bpo11+1 (32 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
freerdp22.10.0+dfsg1-1 ... 2.11.7+dfsg1-6~deb12u1 (13 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
freerdp33.15.0+dfsg-2.1 ... 3.32.1+dfsg-1~bpo13+1 (49 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
freerdp33.15.0+dfsg-2.1 ... 3.26.0+dfsg-1~bpo13+1 (32 versions)
  • every version up to 3.26.0+dfsg-1: fixed in 3.26.0+dfsg-1
—

Weakness Classification(2)

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

Additional Vendor Advisories

(2)

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 10× in last 7d / 32× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 226 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 126 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  2. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  3. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  4. 2026-10-18 03:39 UTCEG score recompute
  5. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  6. 2026-10-17 13:59 UTCEG score recompute
  7. 2026-10-17 13:59 UTCVendor advisory
  8. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  9. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  10. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  11. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  12. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  13. 2026-10-12 16:05 UTCEG score recompute
  14. 2026-10-11 19:47 UTCEG score recompute
  15. 2026-10-11 17:01 UTCEG score recompute
  16. 2026-10-11 14:27 UTCEG score recompute
  17. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  18. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  19. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  20. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  21. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  22. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  23. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  24. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  25. 2026-10-03 14:48 UTCOSV refresh
Show 75 more
  1. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  2. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  3. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  4. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  5. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  6. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  7. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  8. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  9. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  10. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  11. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  12. 2026-09-14 06:22 UTCEG score recompute
  13. 2026-09-14 06:22 UTCVendor advisory
  14. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  15. 2026-09-13 01:06 UTCOSV refresh
  16. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  17. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  18. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  19. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  20. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  21. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  22. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  23. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  24. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  25. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  26. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  27. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  28. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  29. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  30. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  31. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  32. 2026-08-25 04:17 UTCEG score recompute
  33. 2026-08-25 04:17 UTCVendor advisory
  34. 2026-08-23 14:11 UTCEG score recompute
  35. 2026-08-23 14:11 UTCVendor advisory
  36. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  37. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  38. 2026-08-21 14:59 UTCEG score recompute
  39. 2026-08-21 14:59 UTCVendor advisory
  40. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  41. 2026-08-20 21:50 UTCVendor advisory
  42. 2026-08-20 10:24 UTCEG score recompute
  43. 2026-08-20 10:24 UTCVendor advisory
  44. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  45. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  46. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  47. 2026-08-17 06:51 UTCEG score recompute
  48. 2026-08-17 06:51 UTCVendor advisory
  49. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  50. 2026-08-16 06:05 UTCEG score recompute
  51. 2026-08-16 06:05 UTCVendor advisory
  52. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  53. 2026-08-15 18:41 UTCEG score recompute
  54. 2026-08-15 18:41 UTCVendor advisory
  55. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  56. 2026-08-14 23:18 UTCVendor advisory
  57. 2026-08-14 11:52 UTCVendor advisory
  58. 2026-08-14 00:27 UTCEG score recompute
  59. 2026-08-14 00:27 UTCVendor advisory
  60. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  61. 2026-08-13 08:54 UTCVendor advisory
  62. 2026-08-12 21:29 UTCEG score recompute
  63. 2026-08-12 21:29 UTCVendor advisory
  64. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  65. 2026-08-12 10:05 UTCVendor advisory
  66. 2026-08-11 22:35 UTCEG score recompute
  67. 2026-08-11 22:35 UTCVendor advisory
  68. 2026-08-11 13:43 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  69. 2026-08-11 11:10 UTCEG score recompute
  70. 2026-08-11 11:10 UTCVendor advisory
  71. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  72. 2026-08-10 23:43 UTCVendor advisory
  73. 2026-08-10 04:18 UTCVendor advisory
  74. 2026-08-09 16:53 UTCEG score recompute
  75. 2026-08-09 16:53 UTCVendor advisory

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-44421?
CVE-2026-44421 is a high-severity vulnerability; its CVE record was published on May 29, 2026. FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client by sending crafted RDPGFX PDUs. The bug is in gdiCacheToSurface: it validates a destination rectangle that is clamped to UINT16MAX,…
When was the CVE record for CVE-2026-44421 published?
The CVE record for CVE-2026-44421 was published on May 29, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 27, 2026; the record at its source may have been updated since.
Is CVE-2026-44421 actively exploited?
CVE-2026-44421 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (52nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-44421?
CVE-2026-44421 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-44421?
A fix for CVE-2026-44421 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-44421 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-44421

Explore →

Is Your Infrastructure Affected by CVE-2026-44421?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs