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TI-2026-26325 Aliases CVE-2026-33984

FreeRDP: ClearCodec resize_vbar_entry() Heap OOB Write

Priority LOW 35CWE-122Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
High
Impact type
Code execution
Confidentiality · integrity · availability
High · High · 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-122 and the CVSS impact.

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, in resize_vbar_entry() in libfreerdp/codec/clear.c, vBarEntry->size is updated to vBarEntry->count before the winpr_aligned_recalloc() call. If realloc fails, size is inflated while pixels still points to the old, smaller buffer. On a subsequent call where count <= size (the inflated value), realloc is skipped. The caller then writes count * bpp bytes of attacker-controlled pixel data into the undersized buffer, causing a heap buffer overflow. This issue has been patched in version 3.24.2.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00405 34th 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
Total

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-2026-33984
  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