HighFix available
tesseract — security advisory
Tesseract is an open source OCR engine. In version 5.5.3 and earlier, UNICHARSET::load_via_fgets in src/ccutil/unicharset.cpp trusts the declared unichar count as a loop bound and uses id as an unchecked index into the unichars vector. unichar_insert_backwards_compatible can leave the vector unchanged for an empty, duplicate, or already-encodable representation, causing id to become larger than unichars.size(). Subsequent set_* calls and the write to unichars[id].properties.enabled then write UNICHAR_PROPERTIES beyond the vector during initialization in both the default LSTM and legacy engines, causing heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.
- Products
- tesseract
- Affected versions
- 3.02.02-1, 3.03.02-3, 3.04.00-5ubuntu1, 3.04.01-2, 3.04.01-4, 3.04.01-6, 3.04.01-6build1, 3.04.01-6build2, 4.00~git2188-cdc35338-4build1, 4.00~git2188-cdc35338-5, 4.00~git2207-766b7bd6-3.1, 4.00~git2219-40f43111-1.2, 4.00~git2288-10f4998a-2, 4.1.0-1, 4.1.0-2, 4.1.1-1, 4.1.1-2, 4.1.1-2.1, 4.1.1-2.1build1, 4.1.1-2build1, 4.1.1-2build2, 5.3.0-2build1, 5.3.3-1, 5.3.3-1build1, 5.3.4-1, 5.3.4-1build3, 5.3.4-1build4, 5.3.4-1build5, 5.5.0-1, 5.5.0-1.1, 5.5.0-1build1
- Fixed versions
- 3.03.02-3ubuntu0.1~esm1, 3.04.01-4ubuntu0.1~esm1, 4.00~git2288-10f4998a-2ubuntu0.1~esm1, 4.1.1-2.1ubuntu0.1~esm1, 4.1.1-2ubuntu0.1~esm1, 5.3.4-1ubuntu0.1~esm1, 5.5.0-1ubuntu0.1~esm1
- CVEs
- CVE-2026-88052
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:30 UTC · Revision 1
Source evidence
Tesseract is an open source OCR engine. In version 5.5.3 and earlier, UNICHARSET::load_via_fgets in src/ccutil/unicharset.cpp trusts the declared unichar count as a loop bound and uses id as an unchecked index into the unichars vector. unichar_insert_backwards_compatible can leave the vector unchanged for an empty, duplicate, or already-encodable representation, causing id to become larger than unichars.size(). Subsequent set_* calls and the write to unichars[id].properties.enabled then write UNICHAR_PROPERTIES beyond the vector during initialization in both the default LSTM and legacy engines, causing heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.
osv:UBUNTU-CVE-2026-88052
tesseract
Fixed versions: 3.03.02-3ubuntu0.1~esm1
tesseract
Fixed versions: 3.04.01-4ubuntu0.1~esm1
tesseract
Fixed versions: 4.00~git2288-10f4998a-2ubuntu0.1~esm1
tesseract
Fixed versions: 4.1.1-2ubuntu0.1~esm1
tesseract
Fixed versions: 4.1.1-2.1ubuntu0.1~esm1
tesseract
Fixed versions: 5.3.4-1ubuntu0.1~esm1
tesseract
Fixed versions: Not specified
tesseract
Fixed versions: 5.5.0-1ubuntu0.1~esm1
Complete source record
{
"id": "de247a36e8ccf5a05d2a340acc345be5ba8ca4ae3e036d79bc6221289b360a83",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-88052",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-88052",
"summary": "Tesseract is an open source OCR engine. In version 5.5.3 and earlier, UNICHARSET::load_via_fgets in src/ccutil/unicharset.cpp trusts the declared unichar count as a loop bound and uses id as an unchecked index into the unichars vector. unichar_insert_backwards_compatible can leave the vector unchanged for an empty, duplicate, or already-encodable representation, causing id to become larger than unichars.size(). Subsequent set_* calls and the write to unichars[id].properties.enabled then write UNICHAR_PROPERTIES beyond the vector during initialization in both the default LSTM and legacy engines, causing heap corruption, a crash, or potentially controlled corruption. No fixed release is available as of this review.",
"evidence": "osv:UBUNTU-CVE-2026-88052",
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{
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{
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{
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"value": "4.00~git2207-766b7bd6-3.1",
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{
"value": "4.00~git2219-40f43111-1.2",
"evidence": "/affected/2/versions"
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{
"value": "4.00~git2288-10f4998a-2",
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},
{
"name": {
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{
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"affected_versions": [
{
"value": "4.1.0-1",
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{
"value": "4.1.0-2",
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{
"value": "4.1.1-1",
"evidence": "/affected/3/versions"
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{
"value": "4.1.1-2",
"evidence": "/affected/3/versions"
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{
"value": "4.1.1-2build1",
"evidence": "/affected/3/versions"
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{
"value": "4.1.1-2build2",
"evidence": "/affected/3/versions"
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]
},
{
"name": {
"value": "tesseract",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.1.1-2.1ubuntu0.1~esm1",
"evidence": "/affected/4/ranges"
}
],
"affected_versions": [
{
"value": "4.1.1-2.1",
"evidence": "/affected/4/versions"
},
{
"value": "4.1.1-2.1build1",
"evidence": "/affected/4/versions"
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},
{
"name": {
"value": "tesseract",
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{
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}
],
"affected_versions": [
{
"value": "5.3.0-2build1",
"evidence": "/affected/5/versions"
},
{
"value": "5.3.3-1",
"evidence": "/affected/5/versions"
},
{
"value": "5.3.3-1build1",
"evidence": "/affected/5/versions"
},
{
"value": "5.3.4-1",
"evidence": "/affected/5/versions"
},
{
"value": "5.3.4-1build3",
"evidence": "/affected/5/versions"
},
{
"value": "5.3.4-1build4",
"evidence": "/affected/5/versions"
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{
"value": "5.3.4-1build5",
"evidence": "/affected/5/versions"
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},
{
"name": {
"value": "tesseract",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
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"affected_versions": [
{
"value": "5.5.0-1build1",
"evidence": "/affected/6/versions"
},
{
"value": "5.5.0-1.1",
"evidence": "/affected/6/versions"
}
]
},
{
"name": {
"value": "tesseract",
"evidence": "/affected/7/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.5.0-1ubuntu0.1~esm1",
"evidence": "/affected/7/ranges"
}
],
"affected_versions": [
{
"value": "5.5.0-1",
"evidence": "/affected/7/versions"
},
{
"value": "5.5.0-1build1",
"evidence": "/affected/7/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2026-88052",
"aliases": [
"UBUNTU-CVE-2026-88052"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
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"package": {
"name": "tesseract",
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"ecosystem": "Ubuntu:Pro:14.04:LTS"
},
"versions": [
"3.02.02-1",
"3.03.02-3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88052.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libtesseract3",
"binary_version": "3.03.02-3ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr",
"binary_version": "3.03.02-3ubuntu0.1~esm1"
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],
"availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
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],
"package": {
"name": "tesseract",
"purl": "pkg:deb/ubuntu/tesseract?arch=source&distro=esm-apps-legacy%2Fxenial",
"ecosystem": "Ubuntu:Pro:16.04:LTS"
},
"versions": [
"3.04.00-5ubuntu1",
"3.04.01-2",
"3.04.01-4"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88052.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libtesseract3",
"binary_version": "3.04.01-4ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr",
"binary_version": "3.04.01-4ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr-all",
"binary_version": "3.04.01-4ubuntu0.1~esm1"
}
],
"availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
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{
"introduced": "0"
},
{
"fixed": "4.00~git2288-10f4998a-2ubuntu0.1~esm1"
}
]
}
],
"package": {
"name": "tesseract",
"purl": "pkg:deb/ubuntu/tesseract?arch=source&distro=esm-apps%2Fbionic",
"ecosystem": "Ubuntu:Pro:18.04:LTS"
},
"versions": [
"3.04.01-6",
"3.04.01-6build1",
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},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libtesseract4",
"binary_version": "4.00~git2288-10f4998a-2ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr",
"binary_version": "4.00~git2288-10f4998a-2ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr-all",
"binary_version": "4.00~git2288-10f4998a-2ubuntu0.1~esm1"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
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{
"introduced": "0"
},
{
"fixed": "4.1.1-2ubuntu0.1~esm1"
}
]
}
],
"package": {
"name": "tesseract",
"purl": "pkg:deb/ubuntu/tesseract?arch=source&distro=esm-apps%2Ffocal",
"ecosystem": "Ubuntu:Pro:20.04:LTS"
},
"versions": [
"4.1.0-1",
"4.1.0-2",
"4.1.1-1",
"4.1.1-2",
"4.1.1-2build1",
"4.1.1-2build2"
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"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88052.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libtesseract4",
"binary_version": "4.1.1-2ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr",
"binary_version": "4.1.1-2ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr-all",
"binary_version": "4.1.1-2ubuntu0.1~esm1"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
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{
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},
{
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}
]
}
],
"package": {
"name": "tesseract",
"purl": "pkg:deb/ubuntu/tesseract?arch=source&distro=esm-apps%2Fjammy",
"ecosystem": "Ubuntu:Pro:22.04:LTS"
},
"versions": [
"4.1.1-2.1",
"4.1.1-2.1build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88052.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libtesseract4",
"binary_version": "4.1.1-2.1ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr",
"binary_version": "4.1.1-2.1ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr-all",
"binary_version": "4.1.1-2.1ubuntu0.1~esm1"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
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{
"introduced": "0"
},
{
"fixed": "5.3.4-1ubuntu0.1~esm1"
}
]
}
],
"package": {
"name": "tesseract",
"purl": "pkg:deb/ubuntu/tesseract?arch=source&distro=esm-apps%2Fnoble",
"ecosystem": "Ubuntu:Pro:24.04:LTS"
},
"versions": [
"5.3.0-2build1",
"5.3.3-1",
"5.3.3-1build1",
"5.3.4-1",
"5.3.4-1build3",
"5.3.4-1build4",
"5.3.4-1build5"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88052.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libtesseract5",
"binary_version": "5.3.4-1ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr",
"binary_version": "5.3.4-1ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr-all",
"binary_version": "5.3.4-1ubuntu0.1~esm1"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
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{
"introduced": "0"
}
]
}
],
"package": {
"name": "tesseract",
"purl": "pkg:deb/ubuntu/tesseract?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"5.5.0-1build1",
"5.5.0-1.1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88052.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libtesseract5",
"binary_version": "5.5.0-1.1"
},
{
"binary_name": "tesseract-ocr",
"binary_version": "5.5.0-1.1"
},
{
"binary_name": "tesseract-ocr-all",
"binary_version": "5.5.0-1.1"
}
]
}
},
{
"ranges": [
{
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{
"introduced": "0"
},
{
"fixed": "5.5.0-1ubuntu0.1~esm1"
}
]
}
],
"package": {
"name": "tesseract",
"purl": "pkg:deb/ubuntu/tesseract?arch=source&distro=esm-apps%2Fresolute",
"ecosystem": "Ubuntu:Pro:26.04:LTS"
},
"versions": [
"5.5.0-1",
"5.5.0-1build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-88052.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libtesseract5",
"binary_version": "5.5.0-1ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr",
"binary_version": "5.5.0-1ubuntu0.1~esm1"
},
{
"binary_name": "tesseract-ocr-all",
"binary_version": "5.5.0-1ubuntu0.1~esm1"
}
],
"availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}
}
],
"modified": "2026-10-17T13:01:15.494596845Z",
"provider": "osv",
"upstream": [
"CVE-2026-88052"
],
"references": [
"https://ubuntu.com/security/CVE-2026-88052",
"https://www.cve.org/CVERecord?id=CVE-2026-88052",
"https://ubuntu.com/security/notices/USN-8882-1"
]
},
"related_cves": [
{
"value": "CVE-2026-88052",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 361397,
"published_at": "2026-09-10T18:18:00+00:00"
}