CVE-2026-64620

CRITICALNVD 9.19.8
EchelonGraph scoreMEDIUM confidence

“▲” beside the score: it is higher than NVD's CVSS score.

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-20. NVD baseline CVSS 9.1; sources differ by 0.7.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 4 sources updated this week

Also known asEUVD-2026-45935 (ENISA EUVD) · GHSA-xmhx-cqxp-qrgq (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
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).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.9%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

FreeRDP before 3.28.0 (affected <=3.27.1) contains a heap-based buffer overflow in crypto_rsa_common() (libfreerdp/crypto/crypto.c). The function writes the modular-exponentiation result into the caller's output buffer via BN_bn2bin() and only afterward checks output_length > out_length, so out-of-bounds bytes are written before the bounds check. On the server side, when a client selects RDP Standard Security, the encrypted client random is decrypted into a fixed 32-byte buffer. Because the server publishes its RSA public key, an unauthenticated attacker can forge a ciphertext whose decrypted value is up to the full modulus length (e.g. 256 bytes for RSA-2048), overflowing the 32-byte heap buffer by up to ~224 attacker-controlled bytes pre-authentication, resulting in denial of service.

CVSS v3
9.1
EG Score
9.8CRITICALmedium confidence
EG Risk
59
EG Risk 59/100

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)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.9% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (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
0.9%
EPSS %ILE
59th
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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.9% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-26). 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 or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days 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 or medium mission impact; Attend at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable yes (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)3 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

July 20, 2026

Last Modified

July 28, 2026

Advisory Details (3)

Auto-updated Sep 16, 2026
Patch available. Sources: github_commit, github.
Web page

FreeRDP before 3.28.0 Heap Buffer Overflow via crypto_rsa_common | Advisories | VulnCheck

https://www.vulncheck.com/advisories/freerdp-before-heap-buffer-overflow-via-crypto-rsa-common
GitHub advisoryMentions a patch (unverified)

Pre-auth server heap overflow: `crypto_rsa_common` writes the decrypted client random with `BN_bn2bin` before checking the 32-byte output buffer · Advisory · FreeRDP/FreeRDP · GitHub

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-pjqx-v446-x7fc
GitHub commit

commit 1f7a716d39b5 (FreeRDP/FreeRDP)

Fix landed in FreeRDP/FreeRDP commit 1f7a716d39b5 — awaiting tagged release

https://github.com/FreeRDP/FreeRDP/commit/1f7a716d39b5605bb8a83b0c3c97a6ce386609ef

Vendor Advisories for CVE-2026-64620(3)

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 / EcosystemFix (by version range) / PatchReleasedSource
redhatfreerdp-2:3.10.3-3.el10_0.112026-08-24redhat
redhatfreerdp-2:3.10.3-12.el10_2.82026-08-13redhat

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 ... 3.27.1+dfsg-1 (35 versions)
  • every version up to 3.28.0+dfsg-1: fixed in 3.28.0+dfsg-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 26× in last 7d / 90× 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 556 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 456 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  2. 2026-10-27 03:17 UTCEG score recompute
  3. 2026-10-27 03:17 UTCVendor advisory
  4. 2026-10-27 03:16 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  6. 2026-10-25 21:43 UTCEG score recompute
  7. 2026-10-25 21:43 UTCVendor advisory
  8. 2026-10-25 21:43 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  10. 2026-10-25 14:12 UTCEG score recompute
  11. 2026-10-24 19:58 UTCEG score recompute
  12. 2026-10-24 19:58 UTCVendor advisory
  13. 2026-10-24 19:58 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  14. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  15. 2026-10-23 18:29 UTCEG score recompute
  16. 2026-10-23 18:29 UTCVendor advisory
  17. 2026-10-23 18:29 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  19. 2026-10-22 17:00 UTCEG score recompute
  20. 2026-10-22 17:00 UTCVendor advisory
  21. 2026-10-22 16:59 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  23. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  24. 2026-10-21 15:28 UTCEG score recompute
  25. 2026-10-21 15:28 UTCVendor advisory
Show 75 more
  1. 2026-10-21 15:28 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  2. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  3. 2026-10-20 13:59 UTCEG score recompute
  4. 2026-10-20 13:59 UTCVendor advisory
  5. 2026-10-20 13:58 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  7. 2026-10-19 12:28 UTCEG score recompute
  8. 2026-10-19 12:28 UTCVendor advisory
  9. 2026-10-19 12:27 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  10. 2026-10-18 10:45 UTCVendor advisory
  11. 2026-10-18 10:44 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-18 03:22 UTCEG score recompute
  13. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  14. 2026-10-17 09:14 UTCEG score recompute
  15. 2026-10-17 09:14 UTCVendor advisory
  16. 2026-10-17 09:14 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  18. 2026-10-16 07:43 UTCEG score recompute
  19. 2026-10-16 07:43 UTCVendor advisory
  20. 2026-10-16 07:43 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  22. 2026-10-15 06:13 UTCEG score recompute
  23. 2026-10-15 06:13 UTCVendor advisory
  24. 2026-10-15 06:13 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  26. 2026-10-14 01:49 UTCEG score recompute
  27. 2026-10-14 01:49 UTCVendor advisory
  28. 2026-10-14 01:49 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  29. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  30. 2026-10-12 22:02 UTCEG score recompute
  31. 2026-10-12 22:02 UTCVendor advisory
  32. 2026-10-12 22:01 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  33. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  34. 2026-10-12 15:47 UTCEG score recompute
  35. 2026-10-12 06:09 UTCVendor advisory
  36. 2026-10-12 06:08 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  37. 2026-10-11 19:32 UTCEG score recompute
  38. 2026-10-11 16:47 UTCEG score recompute
  39. 2026-10-11 14:08 UTCEG score recompute
  40. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  41. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  42. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  43. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  44. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  45. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  46. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  47. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  48. 2026-10-04 14:57 UTCEG score recompute
  49. 2026-10-04 14:57 UTCVendor advisory
  50. 2026-10-04 14:57 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  51. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  52. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  53. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  54. 2026-10-01 12:32 UTCVendor advisory
  55. 2026-10-01 12:32 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  56. 2026-10-01 07:46 UTCEG score recompute
  57. 2026-10-01 07:46 UTCVendor advisory
  58. 2026-10-01 07:45 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  59. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  60. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  61. 2026-09-28 10:26 UTCVendor advisory
  62. 2026-09-28 10:26 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  63. 2026-09-28 06:26 UTCEG score recompute
  64. 2026-09-28 06:26 UTCVendor advisory
  65. 2026-09-28 06:26 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  66. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  67. 2026-09-24 13:10 UTCVendor advisory
  68. 2026-09-24 13:10 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  69. 2026-09-24 08:21 UTCVendor advisory
  70. 2026-09-24 08:21 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  71. 2026-09-24 03:30 UTCEG score recompute
  72. 2026-09-24 03:30 UTCVendor advisory
  73. 2026-09-24 03:30 UTCGHSA enrichmentGHSA-xmhx-cqxp-qrgq · GitHub severity CRITICAL · GitHub CVSS 9.8
  74. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.9% · 56th percentile
  75. 2026-09-23 09:43 UTCVendor advisory

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

Frequently asked(5)

What is CVE-2026-64620?
CVE-2026-64620 is a critical-severity vulnerability; its CVE record was published on July 20, 2026. FreeRDP before 3.28.0 (affected <=3.27.1) contains a heap-based buffer overflow in cryptorsacommon() (libfreerdp/crypto/crypto.c). The function writes the modular-exponentiation result into the caller's output buffer via BNbn2bin() and only afterward checks outputlength > out_length, so…
When was CVE-2026-64620 made public?
CVE-2026-64620 was made public on July 6, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on July 20, 2026. EchelonGraph's copy of the record carries a last-modified date of July 28, 2026; the record at its source may have been updated since.
Is CVE-2026-64620 actively exploited?
CVE-2026-64620 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.9% probability of exploitation in the next 30 days (59th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64620?
CVE-2026-64620 has a CVSS v3 base score of 9.1 (NVD). EchelonGraph synthesises NVD + FIRST EPSS + GHSA into a combined EG score of 9.8 (CRITICAL).
How do I remediate CVE-2026-64620?
A fix for CVE-2026-64620 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64620 are linked in the Vendor Advisories panel on this page.

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