CVE-2026-75589
Net::OAuth versions before 0.33 for Perl check HMAC-SHA1, HMAC-SHA256 and PLAINTEXT signatures with a non-constant-time comparison in verify.
Each of the three compares the signature carried in the message against the locally computed one with the eq operator, which returns as soon as the two strings differ. The time taken to reject a signature varies with the length of the matching prefix. RSA-SHA1 is not affected, as it verifies through the RSA key object rather than by comparing strings.
A client that can submit messages and time the replies may recover a valid signature one byte at a time rather than searching the whole signature space. Under PLAINTEXT the value compared against is the signature key itself, so the search recovers consumer_secret and token_secret.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.51%
- Percentil entre todas las CVEs puntuadas: 41
- 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
T1212Exploitation for Credential Accesscredential access90 % - Impacto secundario
T1552.007Container APIcredential access75 %
Red sin autenticación (AV:N/PR:N/UI:N). Timing attack en comparación de firmas HMAC permite recuperar secretos de autenticación (consumer_secret, token_secret) byte a byte.
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-208
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-75589",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-75589",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-08-26T19:43:43.373927Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
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"cvssData": {
"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:H/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 3.6,
"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",
"lessThan": "0.33",
"versionType": "custom"
}
],
"packageURL": "pkg:cpan/Net-OAuth",
"packageName": "Net-OAuth",
"programFiles": [
"lib/Net/OAuth/SignatureMethod/HMAC_SHA1.pm",
"lib/Net/OAuth/SignatureMethod/HMAC_SHA256.pm",
"lib/Net/OAuth/SignatureMethod/PLAINTEXT.pm"
],
"collectionURL": "https://cpan.org/modules",
"defaultStatus": "unaffected",
"programRoutines": [
{
"name": "Net::OAuth::SignatureMethod::HMAC_SHA1::verify"
},
{
"name": "Net::OAuth::SignatureMethod::HMAC_SHA256::verify"
},
{
"name": "Net::OAuth::SignatureMethod::PLAINTEXT::verify"
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"published": "2026-08-19T08:17:13.970",
"references": [
{
"url": "https://github.com/vurtdev/Net-OAuth/commit/a1a16b58add85668ef4fcda642a486ceed098eba.patch",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
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{
"url": "https://github.com/vurtdev/Net-OAuth/security/advisories/GHSA-g8xr-69p3-gw56",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
},
{
"url": "https://metacpan.org/release/RRWO/Net-OAuth-0.33/changes",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
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{
"url": "http://www.openwall.com/lists/oss-security/2026/08/19/3",
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
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"description": [
{
"lang": "en",
"value": "CWE-208"
}
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],
"descriptions": [
{
"lang": "en",
"value": "Net::OAuth versions before 0.33 for Perl check HMAC-SHA1, HMAC-SHA256 and PLAINTEXT signatures with a non-constant-time comparison in verify.\n\nEach of the three compares the signature carried in the message against the locally computed one with the eq operator, which returns as soon as the two strings differ. The time taken to reject a signature varies with the length of the matching prefix. RSA-SHA1 is not affected, as it verifies through the RSA key object rather than by comparing strings.\n\nA client that can submit messages and time the replies may recover a valid signature one byte at a time rather than searching the whole signature space. Under PLAINTEXT the value compared against is the signature key itself, so the search recovers consumer_secret and token_secret."
}
],
"lastModified": "2026-08-26T20:17:59.960",
"sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
}