CVE-2026-72889
Net::OAuth versions before 0.33 for Perl allow the sender to choose the signature algorithm in verify.
verify resolves the signature method class from the signature_method parameter of the incoming message. signature_method is required on every request, so the algorithm used to check a signature is chosen by whoever sent it, and nothing lets the verifying party pin the method instead. When a message names HMAC-SHA1 or HMAC-SHA256, the key is derived from consumer_secret and token_secret rather than from the key the provider deployed.
A provider deployed on RSA-SHA1 holds only the consumer public key, and RFC 5849 does not use consumer_secret for that method, so the required parameter is filled with a placeholder.
Leer descripción completaMostrar menos
A client that names HMAC-SHA1 instead has its signature checked against that placeholder, so a guessable one is enough to forge requests for any consumer key and token.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 9.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.45%
- Percentil entre todas las CVEs puntuadas: 37
- 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 access95 % - Impacto principal
T1553.003SIP and Trust Provider Hijackingdefense impairment90 %
Vulnerabilidad crítica en Net::OAuth que permite falsificar firmas OAuth: atacante remoto sin privilegios elige el algoritmo de firma, derivando claves de placeholders adivinables, comprometiendo la autenticación (AV:N/PR:N/UI:N).
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-347, CWE-757
Referencias
- https://datatracker.ietf.org/doc/html/rfc5849#section-3.4.2
- https://datatracker.ietf.org/doc/html/rfc5849#section-3.4.3
- https://github.com/vurtdev/Net-OAuth/commit/c467adf45c8d77ac4b92ad78b3eebf949252ba7f.patch
- https://github.com/vurtdev/Net-OAuth/security/advisories/GHSA-c8rm-g5cm-4pf5
- https://metacpan.org/release/RRWO/Net-OAuth-0.33/changes
- http://www.openwall.com/lists/oss-security/2026/08/19/2
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-72889",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-72889",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-08-26T18:02:49.745063Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 9.8,
"attackVector": "NETWORK",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"affectedData": [
{
"repo": "https://github.com/vurtdev/Net-OAuth",
"modules": [
"Net::OAuth"
],
"versions": [
{
"status": "affected",
"version": "0",
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"versionType": "custom"
}
],
"packageURL": "pkg:cpan/Net-OAuth",
"packageName": "Net-OAuth",
"programFiles": [
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],
"collectionURL": "https://cpan.org/modules",
"defaultStatus": "unaffected",
"programRoutines": [
{
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{
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},
{
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}
]
}
]
}
],
"published": "2026-08-19T08:17:13.833",
"references": [
{
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"weaknesses": [
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],
"descriptions": [
{
"lang": "en",
"value": "Net::OAuth versions before 0.33 for Perl allow the sender to choose the signature algorithm in verify.\n\nverify resolves the signature method class from the signature_method parameter of the incoming message. signature_method is required on every request, so the algorithm used to check a signature is chosen by whoever sent it, and nothing lets the verifying party pin the method instead. When a message names HMAC-SHA1 or HMAC-SHA256, the key is derived from consumer_secret and token_secret rather than from the key the provider deployed.\n\nA provider deployed on RSA-SHA1 holds only the consumer public key, and RFC 5849 does not use consumer_secret for that method, so the required parameter is filled with a placeholder. A client that names HMAC-SHA1 instead has its signature checked against that placeholder, so a guessable one is enough to forge requests for any consumer key and token."
}
],
"lastModified": "2026-08-26T19:17:00.557",
"sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
}