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TI-2026-26324 Aliases CVE-2026-33983

FreeRDP: Progressive Codec Quant BYTE Underflow - UB + CPU DoS

Priority LOW 29CWE-190Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 22 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-190 and the CVSS impact.

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, progressive_decompress_tile_upgrade() detects a mismatch via progressive_rfx_quant_cmp_equal() but only emits WLog_WARN, execution continues. The wrapped value (247) is used as a shift exponent, causing undefined behavior and an approximately 80 billion iteration loop (CPU DoS). This issue has been patched in version 3.24.2.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00442 38th percentileScored 2026-11-07
Fix Partial FreeRDP (FreeRDP): 3.24.2Red Hat: 14 advisoriesRed Hat: 22 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
FreeRDPFreeRDPbefore 3.24.23.24.2Patch availableCNA
  • FreeRDP VendorFreeRDP Affected before 3.24.2 Fixed in 3.24.2 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*before 3.24.2VulnerableFreeRDP
  • cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:* Versions before 3.24.2 Vulnerable ·FreeRDP

Remediation

  • Fix · CNA FreeRDP (FreeRDP) Fixed in 3.24.2

Red Hat 14 advisories

  • RHSA-2026:19349 Released 2026-05-19 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream (v. 9) freerdp-2:2.11.7-7.el9_8.1, freerdp-libs-2:2.11.7-7.el9_8.1, libwinpr-2:2.11.7-7.el9_8.1
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) freerdp-devel-2:2.11.7-7.el9_8.1, libwinpr-devel-2:2.11.7-7.el9_8.1
  • RHSA-2026:19033 Released 2026-05-19 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream (v. 10) freerdp-2:3.10.3-12.el10_2.2, freerdp-libs-2:3.10.3-12.el10_2.2, libwinpr-2:3.10.3-12.el10_2.2
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) freerdp-devel-2:3.10.3-12.el10_2.2, freerdp-server-2:3.10.3-12.el10_2.2, libwinpr-devel-2:3.10.3-12.el10_2.2
  • RHSA-2026:12359 Released 2026-04-30 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) freerdp-2:2.2.0-12.el8_8.6, freerdp-libs-2:2.2.0-12.el8_8.6, libwinpr-2:2.2.0-12.el8_8.6 +1
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) freerdp-2:2.2.0-12.el8_8.6, freerdp-libs-2:2.2.0-12.el8_8.6, libwinpr-2:2.2.0-12.el8_8.6 +1
Show 11 more Red Hat advisories
  • RHSA-2026:12388 Released 2026-04-30 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) freerdp-2:2.2.0-7.el8_6.6, freerdp-libs-2:2.2.0-7.el8_6.6, libwinpr-2:2.2.0-7.el8_6.6 +1
    • Red Hat Enterprise Linux AppStream E4S (v.8.6) freerdp-2:2.2.0-7.el8_6.6, freerdp-libs-2:2.2.0-7.el8_6.6, libwinpr-2:2.2.0-7.el8_6.6 +1
    • Red Hat Enterprise Linux AppStream TUS (v.8.6) freerdp-2:2.2.0-7.el8_6.6, freerdp-libs-2:2.2.0-7.el8_6.6, libwinpr-2:2.2.0-7.el8_6.6 +1
  • RHSA-2026:11649 Released 2026-04-29 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) freerdp-2:2.2.0-13.el8_4, freerdp-libs-2:2.2.0-13.el8_4, libwinpr-2:2.2.0-13.el8_4 +1
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) freerdp-2:2.2.0-13.el8_4, freerdp-libs-2:2.2.0-13.el8_4, libwinpr-2:2.2.0-13.el8_4 +1
  • RHSA-2026:11651 Released 2026-04-29 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream AUS (v. 8.2) freerdp-2:2.0.0-46.rc4.el8_2.11, freerdp-libs-2:2.0.0-46.rc4.el8_2.11, libwinpr-2:2.0.0-46.rc4.el8_2.11 +1
  • RHSA-2026:11336 Released 2026-04-28 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) freerdp-2:2.4.1-6.el9_2.7, freerdp-libs-2:2.4.1-6.el9_2.7, libwinpr-2:2.4.1-6.el9_2.7
  • RHSA-2026:11333 Released 2026-04-28 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) freerdp-2:3.10.3-3.el10_0.6, freerdp-libs-2:3.10.3-3.el10_0.6, libwinpr-2:3.10.3-3.el10_0.6
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) freerdp-devel-2:3.10.3-3.el10_0.6, freerdp-server-2:3.10.3-3.el10_0.6, libwinpr-devel-2:3.10.3-3.el10_0.6
  • RHSA-2026:11332 Released 2026-04-28 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) freerdp-2:2.4.1-3.el9_0.5, freerdp-libs-2:2.4.1-3.el9_0.5, libwinpr-2:2.4.1-3.el9_0.5
  • RHSA-2026:10709 Released 2026-04-27 · Red Hat rating Important
    freerdp security update
    • Red Hat CodeReady Linux Builder EUS (v.9.4) freerdp-devel-2:2.11.2-1.el9_4.6, libwinpr-devel-2:2.11.2-1.el9_4.6
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) freerdp-2:2.11.2-1.el9_4.6, freerdp-libs-2:2.11.2-1.el9_4.6, libwinpr-2:2.11.2-1.el9_4.6
  • RHSA-2026:9656 Released 2026-04-22 · Red Hat rating Important
    freerdp security update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) freerdp-devel-2:2.11.7-1.el9_6.8, libwinpr-devel-2:2.11.7-1.el9_6.8
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) freerdp-2:2.11.7-1.el9_6.8, freerdp-libs-2:2.11.7-1.el9_6.8, libwinpr-2:2.11.7-1.el9_6.8
  • RHSA-2026:8945 Released 2026-04-20 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream (v. 8) freerdp-2:2.11.7-7.el8_10, freerdp-libs-2:2.11.7-7.el8_10, libwinpr-2:2.11.7-7.el8_10 +1
    • Red Hat Enterprise Linux CRB (v. 8) freerdp-devel-2:2.11.7-7.el8_10
  • RHSA-2026:8457 Released 2026-04-16 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream (v. 9) freerdp-2:2.11.7-1.el9_7.6, freerdp-libs-2:2.11.7-1.el9_7.6, libwinpr-2:2.11.7-1.el9_7.6
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) freerdp-devel-2:2.11.7-1.el9_7.6, libwinpr-devel-2:2.11.7-1.el9_7.6
  • RHSA-2026:8458 Released 2026-04-16 · Red Hat rating Important
    freerdp security update
    • Red Hat Enterprise Linux AppStream (v. 10) freerdp-2:3.10.3-5.el10_1.6, freerdp-libs-2:3.10.3-5.el10_1.6, libwinpr-2:3.10.3-5.el10_1.6
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) freerdp-devel-2:3.10.3-5.el10_1.6, freerdp-server-2:3.10.3-5.el10_1.6, libwinpr-devel-2:3.10.3-5.el10_1.6

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat CodeReady Linux Builder EUS (v.9.4)Fixed RHSA-2026:10709
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:9656
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:19033, RHSA-2026:8458
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:8945
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:19349, RHSA-2026:8457
Red Hat Enterprise Linux AppStream AUS (v. 8.2)Fixed RHSA-2026:11651
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:11649
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:12388
Red Hat Enterprise Linux AppStream E4S (v.8.6)Fixed RHSA-2026:12388
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:12359
Red Hat Enterprise Linux AppStream E4S (v.9.0)Fixed RHSA-2026:11332
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:11336
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:11333
Red Hat Enterprise Linux AppStream EUS (v.9.4)Fixed RHSA-2026:10709
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:9656
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:11649
Red Hat Enterprise Linux AppStream TUS (v.8.6)Fixed RHSA-2026:12388
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:12359
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:8945
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:19033, RHSA-2026:8458
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:19349, RHSA-2026:8457
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:11333

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-33983
  2. 2026-10-25 EPSS moved to the below the 50th percentile

References

Patch 2

  • TI-2026-85092 Use-after-free in FreeRDP rdpgfx channel close handling CVSS 4.0CRITICAL 9.3
  • TI-2026-85091 Out-of-bounds write in FreeRDP proxy via bitmap cache v2 capability CVSS 4.0CRITICAL 9.3
  • TI-2026-24435 FreeRDP has a `size_t` underflow in ADPCM decoder leads to heap-buffer-overflow write CVSS 3.1CRITICAL 9.8
  • TI-2023-21373 Out-Of-Bounds Write in FreeRDP CVSS 3.1CRITICAL 9.8
  • TI-2022-08692 Server side NTLM does not properly check parameters in FreeRDP CVSS 3.1CRITICAL 9.1
  • TI-2023-21374 Out-Of-Bounds Read in FreeRDP CVSS 3.1CRITICAL 9.1
See all 336 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences