FKIE_CVE-2026-39373

Vulnerability from fkie_nvd - Published: 2026-04-07 20:16 - Updated: 2026-07-24 21:10
Severity
5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Summary
JWCrypto implements JWK, JWS, and JWE specifications using python-cryptography. Prior to 1.5.7, an unauthenticated attacker can exhaust server memory by sending crafted JWE tokens with ZIP compression. The existing patch for CVE-2024-28102 limits input token size to 250KB but does not validate the decompressed output size. An unauthenticated attacker can cause memory exhaustion on memory-constrained systems. A token under the 250KB input limit can decompress to approximately 100MB. This vulnerability is fixed in 1.5.7.
References
security-advisories@github.comhttps://github.com/latchset/jwcrypto/security/advisories/GHSA-fjrm-76x2-c4q4Exploit, Vendor Advisory
Impacted products
Vendor Product Version
latchset jwcrypto *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "jwcrypto",
          "vendor": "latchset",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.5.7"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:latchset:jwcrypto:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "95859984-CAD0-47DF-AA9E-C0685F460729",
              "versionEndExcluding": "1.5.7",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "JWCrypto implements JWK, JWS, and JWE specifications using python-cryptography. Prior to 1.5.7, an unauthenticated attacker can exhaust server memory by sending crafted JWE tokens with ZIP compression. The existing patch for CVE-2024-28102  limits input token size to 250KB but does not validate the decompressed output size. An unauthenticated attacker can cause memory exhaustion on memory-constrained systems. A token under the 250KB input limit can decompress to approximately 100MB. This vulnerability is fixed in 1.5.7."
    },
    {
      "lang": "es",
      "value": "JWCrypto implementa las especificaciones JWK, JWS y JWE utilizando python-cryptography. Antes de la 1.5.7, un atacante no autenticado puede agotar la memoria del servidor enviando tokens JWE manipulados con compresi\u00f3n ZIP. El parche existente para CVE-2024-28102 limita el tama\u00f1o del token de entrada a 250KB, pero no valida el tama\u00f1o de la salida descomprimida. Un atacante no autenticado puede causar el agotamiento de la memoria en sistemas con recursos de memoria limitados. Un token por debajo del l\u00edmite de entrada de 250KB puede descomprimirse a aproximadamente 100MB. Esta vulnerabilidad est\u00e1 corregida en la versi\u00f3n 1.5.7."
    }
  ],
  "id": "CVE-2026-39373",
  "lastModified": "2026-07-24T21:10:00.143",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-39373",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-04-07T20:22:50.934916Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-04-07T20:16:32.133",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "url": "https://github.com/latchset/jwcrypto/security/advisories/GHSA-fjrm-76x2-c4q4"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-409"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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