CVE-2026-55827 (GCVE-0-2026-55827)
Vulnerability from cvelistv5 – Published: 2026-07-10 19:47 – Updated: 2026-07-15 03:58
VLAI
EPSS
VEX
Title
FreeRDP: Heap out-of-bounds write in RemoteFX (RFX) Cache Bitmap V3 decode
Summary
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.1, FreeRDP clients launched with the non-default /cache:codec:rfx option pass desktop stride and height to RemoteFX decoding for Cache Bitmap V3 data while allocating bitmap->data only for the smaller DstWidth and DstHeight in gdi_Bitmap_Decompress, allowing a malicious RDP server to trigger a heap out-of-bounds write with attacker-controlled offset and content. This issue is fixed in version 3.27.1.
Severity
7.5 (High)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-14 00:00 UTC
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/FreeRDP/FreeRDP/security/advis… | x_refsource_CONFIRM |
| https://github.com/FreeRDP/FreeRDP/pull/12899 | x_refsource_MISC |
| https://github.com/FreeRDP/FreeRDP/commit/e58adf9… | x_refsource_MISC |
| https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.1 | x_refsource_MISC |
Impacted products
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-55827",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-14T00:00:00+00:00",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-07-15T03:58:59.199Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"exploit"
],
"url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-c495-h83v-3prp"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "FreeRDP",
"vendor": "FreeRDP",
"versions": [
{
"status": "affected",
"version": "\u003c 3.27.1"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.1, FreeRDP clients launched with the non-default /cache:codec:rfx option pass desktop stride and height to RemoteFX decoding for Cache Bitmap V3 data while allocating bitmap-\u003edata only for the smaller DstWidth and DstHeight in gdi_Bitmap_Decompress, allowing a malicious RDP server to trigger a heap out-of-bounds write with attacker-controlled offset and content. This issue is fixed in version 3.27.1."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-131",
"description": "CWE-131: Incorrect Calculation of Buffer Size",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-787",
"description": "CWE-787: Out-of-bounds Write",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-07-10T19:47:03.498Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-c495-h83v-3prp",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-c495-h83v-3prp"
},
{
"name": "https://github.com/FreeRDP/FreeRDP/pull/12899",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/FreeRDP/FreeRDP/pull/12899"
},
{
"name": "https://github.com/FreeRDP/FreeRDP/commit/e58adf922ea4c0d5495e59a1fe488d70092e0e3e",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/FreeRDP/FreeRDP/commit/e58adf922ea4c0d5495e59a1fe488d70092e0e3e"
},
{
"name": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.1",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.1"
}
],
"source": {
"advisory": "GHSA-c495-h83v-3prp",
"discovery": "UNKNOWN"
},
"title": "FreeRDP: Heap out-of-bounds write in RemoteFX (RFX) Cache Bitmap V3 decode"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-55827",
"datePublished": "2026-07-10T19:47:03.498Z",
"dateReserved": "2026-06-17T16:29:38.864Z",
"dateUpdated": "2026-07-15T03:58:59.199Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-55827",
"date": "2026-09-17",
"epss": "0.00339",
"percentile": "0.27289"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"product": "FreeRDP",
"vendor": "FreeRDP",
"versions": [
{
"status": "affected",
"version": "\u003c 3.27.1"
}
]
}
],
"source": "security-advisories@github.com"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*",
"matchCriteriaId": "2A25C5E0-4DFB-4BAA-8C4B-6B808F0F8984",
"versionEndExcluding": "3.27.1",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.1, FreeRDP clients launched with the non-default /cache:codec:rfx option pass desktop stride and height to RemoteFX decoding for Cache Bitmap V3 data while allocating bitmap-\u003edata only for the smaller DstWidth and DstHeight in gdi_Bitmap_Decompress, allowing a malicious RDP server to trigger a heap out-of-bounds write with attacker-controlled offset and content. This issue is fixed in version 3.27.1."
}
],
"id": "CVE-2026-55827",
"lastModified": "2026-07-15T05:17:15.187",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.6,
"impactScore": 5.9,
"source": "security-advisories@github.com",
"type": "Secondary"
},
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 2.8,
"impactScore": 5.9,
"source": "nvd@nist.gov",
"type": "Primary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-55827",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-14T00:00:00+00:00",
"version": "2.0.3"
}
}
]
},
"published": "2026-07-10T20:16:48.060",
"references": [
{
"source": "security-advisories@github.com",
"tags": [
"Patch"
],
"url": "https://github.com/FreeRDP/FreeRDP/commit/e58adf922ea4c0d5495e59a1fe488d70092e0e3e"
},
{
"source": "security-advisories@github.com",
"tags": [
"Patch"
],
"url": "https://github.com/FreeRDP/FreeRDP/pull/12899"
},
{
"source": "security-advisories@github.com",
"tags": [
"Release Notes"
],
"url": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.1"
},
{
"source": "security-advisories@github.com",
"tags": [
"Exploit",
"Mitigation",
"Vendor Advisory"
],
"url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-c495-h83v-3prp"
},
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"tags": [
"Exploit",
"Mitigation",
"Vendor Advisory"
],
"url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-c495-h83v-3prp"
}
],
"sourceIdentifier": "security-advisories@github.com",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-131"
},
{
"lang": "en",
"value": "CWE-787"
}
],
"source": "security-advisories@github.com",
"type": "Secondary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Important",
"current_release_date": "2026-08-13T18:23:14+00:00",
"cve": "CVE-2026-55827",
"id": "CVE-2026-55827",
"initial_release_date": "2026-07-10T19:47:03.498000+00:00",
"product_status:fixed": "130",
"product_status:known_affected": "12",
"product_status:known_not_affected": "12",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "FreeRDP: FreeRDP: Remote code execution via heap out-of-bounds write in RemoteFX decoding",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-55827.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "important",
"current_release_date": "2026-09-09T00:16:22Z",
"cve": "CVE-2026-55827",
"id": "CVE-2026-55827",
"initial_release_date": "2026-07-15T05:03:01Z",
"product_status:known_affected": "145",
"product_status:recommended": "21",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-55827",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-55827.json",
"version": "4"
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-55827",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-10T20:15:15.320625Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-07-10T20:15:32.787Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"exploit"
],
"url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-c495-h83v-3prp"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"product": "FreeRDP",
"vendor": "FreeRDP",
"versions": [
{
"status": "affected",
"version": "\u003c 3.27.1"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.1, FreeRDP clients launched with the non-default /cache:codec:rfx option pass desktop stride and height to RemoteFX decoding for Cache Bitmap V3 data while allocating bitmap-\u003edata only for the smaller DstWidth and DstHeight in gdi_Bitmap_Decompress, allowing a malicious RDP server to trigger a heap out-of-bounds write with attacker-controlled offset and content. This issue is fixed in version 3.27.1."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "REQUIRED",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
"version": "3.1"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-131",
"description": "CWE-131: Incorrect Calculation of Buffer Size",
"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-787",
"description": "CWE-787: Out-of-bounds Write",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-07-10T19:47:03.498Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-c495-h83v-3prp",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-c495-h83v-3prp"
},
{
"name": "https://github.com/FreeRDP/FreeRDP/pull/12899",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/FreeRDP/FreeRDP/pull/12899"
},
{
"name": "https://github.com/FreeRDP/FreeRDP/commit/e58adf922ea4c0d5495e59a1fe488d70092e0e3e",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/FreeRDP/FreeRDP/commit/e58adf922ea4c0d5495e59a1fe488d70092e0e3e"
},
{
"name": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.1",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.1"
}
],
"source": {
"advisory": "GHSA-c495-h83v-3prp",
"discovery": "UNKNOWN"
},
"title": "FreeRDP: Heap out-of-bounds write in RemoteFX (RFX) Cache Bitmap V3 decode"
}
},
"cveMetadata": {
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"cveId": "CVE-2026-55827",
"datePublished": "2026-07-10T19:47:03.498Z",
"dateReserved": "2026-06-17T16:29:38.864Z",
"dateUpdated": "2026-07-10T20:15:41.227Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…