CVE-2026-19566
Net::CIDR::Set versions before 0.23 for Perl allow memory exhaustion and malformed set ranges via unbounded IPv6 prefix lengths.
The _encode method accepts any prefix length matching `(0|[1-9][0-9]*)` and passes it to _width2bits(), which builds the mask as `'1' x ($width + 8)`, one character per bit. The _inc() method then unpacks the packed mask into a Perl array of one scalar per byte, so the prefix length alone sets the allocation size: `::/100000000` builds a 100 MB string and a 12.5 million element array.
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The value being tested is parsed, not just the configured ranges: contains() builds a set from its argument, and _guess_coder() tries the IPv4 coder and then the IPv6 coder, so an IPv4-only set expands an oversized IPv6 prefix length before the mixed address width check rejects it.
Any caller that passes untrusted input to contains() or add() can exhaust process memory. A prefix length above 128 is also stored as a range that does not match the requested block: 2001:db8::/129 stringifies back unchanged, contains() of its own base address returns false, and removing it from a set drops the base address while the set still prints as covering it.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.63%
- Percentil entre todas las CVEs puntuadas: 48
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access85 % - Impacto principal
T1499.004Application or System Exploitationimpact90 % - Impacto secundario
T1561.001Disk Content Wipeimpact70 %
Acceso remoto sin autenticación (AV:N, PR:N, UI:N) que causa agotamiento de memoria mediante prefijos IPv6 no validados. El método contains() acepta entrada no confiable y construye estructuras masivas (100 MB strings, millones de elementos).
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-789, CWE-1284
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-19566",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-19566",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-08-12T19:49:22.654200Z"
}
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"cvssMetricV31": [
{
"type": "Secondary",
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"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
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"affected": [
{
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"affectedData": [
{
"repo": "https://github.com/robrwo/perl-Net-CIDR-Set",
"vendor": "RRWO",
"product": "Net::CIDR::Set",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "0.23",
"versionType": "custom"
}
],
"packageName": "Net-CIDR-Set",
"programFiles": [
"lib/Net/CIDR/Set/IPv6.pm",
"lib/Net/CIDR/Set.pm"
],
"collectionURL": "https://cpan.org/modules",
"defaultStatus": "unaffected",
"programRoutines": [
{
"name": "Net::CIDR::Set::IPv6::_encode"
},
{
"name": "Net::CIDR::Set::IPv6::_width2bits"
}
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}
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"published": "2026-08-12T09:17:29.753",
"references": [
{
"url": "https://github.com/robrwo/perl-Net-CIDR-Set/commit/e16b27db676fd1ca671fbb31208a22c1b1ba9724.patch",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
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{
"url": "https://github.com/robrwo/perl-Net-CIDR-Set/security/advisories/GHSA-grjr-r4x5-mx4p",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
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{
"url": "https://metacpan.org/release/RRWO/Net-CIDR-Set-0.23/changes",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
},
{
"url": "https://www.cve.org/CVERecord?id=CVE-2026-49942",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
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],
"vulnStatus": "Deferred",
"weaknesses": [
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"type": "Secondary",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"description": [
{
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"value": "CWE-789"
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{
"lang": "en",
"value": "CWE-1284"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Net::CIDR::Set versions before 0.23 for Perl allow memory exhaustion and malformed set ranges via unbounded IPv6 prefix lengths.\n\nThe _encode method accepts any prefix length matching `(0|[1-9][0-9]*)` and passes it to _width2bits(), which builds the mask as `'1' x ($width + 8)`, one character per bit. The _inc() method then unpacks the packed mask into a Perl array of one scalar per byte, so the prefix length alone sets the allocation size: `::/100000000` builds a 100 MB string and a 12.5 million element array. The value being tested is parsed, not just the configured ranges: contains() builds a set from its argument, and _guess_coder() tries the IPv4 coder and then the IPv6 coder, so an IPv4-only set expands an oversized IPv6 prefix length before the mixed address width check rejects it.\n\nAny caller that passes untrusted input to contains() or add() can exhaust process memory. A prefix length above 128 is also stored as a range that does not match the requested block: 2001:db8::/129 stringifies back unchanged, contains() of its own base address returns false, and removing it from a set drops the base address while the set still prints as covering it."
}
],
"lastModified": "2026-08-26T16:51:19.490",
"sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
}