CVE-2026-22858
Critical · CVSS 9.1FreeRDP — global-buffer-overflow via Base64 decoding out-of-bounds read/write (CWE-125, CWE-787, CWE-758)
- CVSS
- 9.1
- nvd
- EPSS
- —
- KEV
- No
- Class
- oss containerizable
- CWE-125, CWE-758, CWE-787
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, global-buffer-overflow was observed in FreeRDP's Base64 decoding path. The root cause appears to be implementation-defined char signedness: on Arm/AArch64 builds, plain char is treated as unsigned, so the guard c <= 0 can be optimized into a simple c != 0 check. As a result, non-ASCII bytes (e.g., 0x80-0xFF) may bypass the intended range restriction and be used as an index into a global lookup table, causing out-of-bounds access. This vulnerability is fixed in 3.20.1.
Search profile — drives PoC discovery
Ranked PoCs (1) — best first
Heuristic ranking — not yet expert-vetted. Scored on structure + provenance, not execution.
- ★ 0
Recall-favoring discovery; ranking by the Stage-4 scorer (Adam's rubric). Scanner/aggregator repos are hidden.
References
- https://github.com/FreeRDP/FreeRDP/releases/tag/3.20.1
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qmqf-m84q-x896
- https://access.redhat.com/errata/RHSA-2026:19033
- https://access.redhat.com/errata/RHSA-2026:3067
- https://access.redhat.com/errata/RHSA-2026:3068
- https://access.redhat.com/errata/RHSA-2026:3334
- https://access.redhat.com/errata/RHSA-2026:3975
- https://access.redhat.com/errata/RHSA-2026:4121
- https://access.redhat.com/errata/RHSA-2026:4433
- https://access.redhat.com/errata/RHSA-2026:4437
- https://access.redhat.com/errata/RHSA-2026:4438
- https://access.redhat.com/errata/RHSA-2026:4439
Status: enriched · ingested 2026-06-30T06:00:22.000Z · profiled 2026-06-30T18:30:14.000Z