CVE-2026-69247

Description

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. From 44.0.0 until 50.0.0, pkcs7_decrypt_der, pkcs7_decrypt_pem, and pkcs7_decrypt_smime reported the outcome of decrypting a RecipientInfo's encryptedKey in several distinguishable ways, one of which disclosed the exact length recovered from the RSA operation. The same distinction was also observable by timing. An application that decrypts attacker-supplied EnvelopedData and reflects the outcome gives the attacker a Bleichenbacher oracle against the content-encryption key. Decryption ran as RSA PKCS#1 v1.5 decrypt of encryptedKey, build an AES cipher from the result, then AES-CBC decrypt and PKCS#7 unpad. Invalid RSA padding, a valid padding with a bad key length, a correct length with a wrong key, and the real key each failed or succeeded differently. Case 1 is reachable only where the linked library lacks implicit rejection: OpenSSL 3.0 and 3.1, LibreSSL, and BoringSSL. Exploitation requires a service that auto-decrypts untrusted EnvelopedData matching the victim certificate and answers adaptively at high volume, such as an S/MIME gateway or mail filter. This issue is fixed in 50.0.0.

Overview

State: PUBLISHED
Assigner (CNA): GitHub_M
CVSS severity: HIGH
CVSS score: 8.2 / 10
CVSS vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Effective score: 8.2 / 10 HIGH source: CNA overview
CWE(s): CWE-208, CWE-209
Reserved: 2026-08-03
Published: 2026-08-03 21:16 UTC
Last updated: 2026-08-03 21:16 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/69xxx/CVE-2026-69247.json
Linked Threat: CVE-2026-69247 — cryptography: PKCS#7 EnvelopedData decryption exposes a Bleichenbacher oracle through distinguishable errors and timing

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-08-03 22:16:52 UTC
NVD last modified: 2026-08-04 15:16:43 UTC
EPSS score: 0.0018 (probability of exploitation in next 30 days)
EPSS percentile: 7.25% vs all CVEs — higher = more likely to be exploited, as of 2026-08-04

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-52446
Assigner: GitHub_M
Published: Aug 3, 2026, 9:16:32 PM
Updated: Aug 4, 2026, 2:09:24 PM
EUVD base score (CVSS 4.0): 8.2 / 10
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
EUVD-reported EPSS: 0.0000
Vendors: pyca
Products: cryptography (44.0.0, < 50.0.0)
Aliases: GHSA-g6cj-pr64-35w5

ENISA description: cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. From 44.0.0 until 50.0.0, pkcs7_decrypt_der, pkcs7_decrypt_pem, and pkcs7_decrypt_smime reported the outcome of decrypting a RecipientInfo's encryptedKey in several distinguishable ways, one of which disclosed the exact length recovered from the RSA operation. The same distinction was also observable by timing. An application that decrypts attacker-supplied EnvelopedData and reflects the outcome gives the attacker a Bleichenbacher oracle against the content-encryption key. Decryption ran as RSA PKCS#1 v1.5 decrypt of encryptedKey, build an AES cipher from the result, then AES-CBC decrypt and PKCS#7 unpad. Invalid RSA padding, a valid padding with a bad key length, a correct length with a wrong key, and the real key each failed or succeeded differently. Case 1 is reachable only where the linked library lacks implicit rejection: OpenSSL 3.0 and 3.1, LibreSSL, and BoringSSL. Exploitation requires a service that auto-decrypts untrusted EnvelopedData matching the victim certificate and answers adaptively at high volume, such as an S/MIME gateway or mail filter. This issue is fixed in 50.0.0.

EUVD references (3)

Affected products (1)

Vendor	Product	Versions	Platforms
pyca	cryptography	`>= 44.0.0, < 50.0.0` (affected)	—

Vendor references (3)

References embedded in the original CVE record by the assigning CNA.

https://github.com/pyca/cryptography/security/advisories/GHSA-g6cj-pr64-35w5 x_refsource_CONFIRM
https://github.com/pyca/cryptography/pull/15369 x_refsource_MISC
https://github.com/pyca/cryptography/commit/53fccd93413a8d7f07d6d8999681f27b75cffa3f x_refsource_MISC

Web references (0)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

No web references attached yet.

NVD-tagged references (3)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://github.com/pyca/cryptography/commit/53fccd93413a8d7f07d6d8999681f27b75cffa3f security-advisories@github.com
https://github.com/pyca/cryptography/pull/15369 security-advisories@github.com
https://github.com/pyca/cryptography/security/advisories/GHSA-g6cj-pr64-35w5 security-advisories@github.com

Remediations (10)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

CVE-2026-69247 - Vulnerability Details - OpenCVE

web:app.opencve.io

With no current EPSS data or KEV listing, adoption of the fix is still critical for any production environment processing potentially malicious enveloped messages, as the exploit is realistically feasible against such services. Generated by OpenCVE AI on August 4, 2026 at 09:41 UTC.

2026-08-04 20:24 UTC
CVE-2026-69247 | High severity in Pyca Cryptography | CVETodo

web:cvetodo.com

CVE-2026-69247 is a CVSS 8.2 high-severity vulnerability in Pyca's Cryptography. Includes technical details, affected versions, and mitigation steps.

2026-08-04 20:24 UTC
CVE-2026-69247: CVE-2026-69247: Bleichenbacher Oracle in pyca ...

web:gist.github.com

References GitHub Security Advisory GHSA-g6cj-pr64-35w5 Fix Commit 53fccd93 GitHub Pull Request 15369 CVE-2026-69247 Record on CVE .org

2026-08-04 20:24 UTC
Security Update Guide - Microsoft

web:portal.msrc.microsoft.com

The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

2026-08-04 20:24 UTC
CVE-2026-69247 - security-tracker.debian.org

web:security-tracker.debian.org

The information below is based on the following data on fixed versions.

2026-08-04 20:24 UTC
SAP Security Patch Day - June 2026

web:support.sap.com

SAP security Patch Day Bulletin This post shares the information on security notes that remediate vulnerabilities discovered in SAP products. SAP strongly recommends that the customer visits the support portal and applies patches on priority to protect their SAP landscape. On 9th of June 2026 , SAP security patch day saw the release of 15 new security notes.

2026-08-04 20:24 UTC
Addressing Exchange Server May 2026 vulnerability CVE-2026-42897 ...

web:techcommunity.microsoft.com

Hi team, Our organization has successfully implemented the recommended mitigation for CVE - 2026 -42897. However, we are currently experiencing the documented known issues within our environment. Could the Exchange team kindly provide a tentative timeline or ETA for a permanent security update that resolves the underlying vulnerability while addressing these known issues? We would greatly ...

2026-08-04 20:24 UTC
CVE-2026-69247 - vulnerability database | Vulners.com

web:vulners.com

The CVE-2026-69247 entry concerns the Python cryptography package (versions 44.0.0 through 50.0.0) where pkcs7_decrypt_der, pkcs7_decrypt_pem, and pkcs7_decrypt_smime reveal distinguishable outcomes or timing when decrypting an EnvelopedData Recip...

2026-08-04 20:24 UTC
CVE-2026-69247 Common Vulnerabilities and Exposures | SUSE

web:www.suse.com

Secure your Linux systems from CVE-2026-69247 . Stay ahead of potential threats with the latest security updates from SUSE.

2026-08-04 20:24 UTC
CVE-2026-69247 - Info Vulnerability - TheHackerWire

web:www.thehackerwire.com

How do I fix or mitigate CVE-2026-69247 ? To protect against CVE-2026-69247 , you should: (1) Apply the latest security patches from the vendor, (2) Check official security advisories for specific remediation steps, (3) Update affected software to the latest version, and (4) Monitor your systems for any signs of exploitation.

2026-08-04 20:24 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-69247.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "cryptography",
          "vendor": "pyca",
          "versions": [
            {
              "status": "affected",
              "version": ">= 44.0.0, < 50.0.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. From 44.0.0 until 50.0.0, pkcs7_decrypt_der, pkcs7_decrypt_pem, and pkcs7_decrypt_smime reported the outcome of decrypting a RecipientInfo's encryptedKey in several distinguishable ways, one of which disclosed the exact length recovered from the RSA operation. The same distinction was also observable by timing. An application that decrypts attacker-supplied EnvelopedData and reflects the outcome gives the attacker a Bleichenbacher oracle against the content-encryption key. Decryption ran as RSA PKCS#1 v1.5 decrypt of encryptedKey, build an AES cipher from the result, then AES-CBC decrypt and PKCS#7 unpad. Invalid RSA padding, a valid padding with a bad key length, a correct length with a wrong key, and the real key each failed or succeeded differently. Case 1 is reachable only where the linked library lacks implicit rejection: OpenSSL 3.0 and 3.1, LibreSSL, and BoringSSL. Exploitation requires a service that auto-decrypts untrusted EnvelopedData matching the victim certificate and answers adaptively at high volume, such as an S/MIME gateway or mail filter. This issue is fixed in 50.0.0."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "HIGH",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-208",
              "description": "CWE-208: Observable Timing Discrepancy",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-209",
              "description": "CWE-209: Generation of Error Message Containing Sensitive Information",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-03T21:16:32.047Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/pyca/cryptography/security/advisories/GHSA-g6cj-pr64-35w5",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-g6cj-pr64-35w5"
        },
        {
          "name": "https://github.com/pyca/cryptography/pull/15369",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pyca/cryptography/pull/15369"
        },
        {
          "name": "https://github.com/pyca/cryptography/commit/53fccd93413a8d7f07d6d8999681f27b75cffa3f",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pyca/cryptography/commit/53fccd93413a8d7f07d6d8999681f27b75cffa3f"
        }
      ],
      "source": {
        "advisory": "GHSA-g6cj-pr64-35w5",
        "discovery": "UNKNOWN"
      },
      "title": "cryptography: PKCS#7 EnvelopedData decryption exposes a Bleichenbacher oracle through distinguishable errors and timing"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-69247",
    "datePublished": "2026-08-03T21:16:32.047Z",
    "dateReserved": "2026-08-03T19:54:19.852Z",
    "dateUpdated": "2026-08-03T21:16:32.047Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}