Skip to main content

pyca cryptography EUVDEUVD-2026-52446

| CVE-2026-69247 HIGH
Observable Timing Discrepancy (CWE-208)
2026-08-03 GitHub_M GHSA-g6cj-pr64-35w5
Python Information Disclosure Oracle OpenSSL Cryptography Suse
8.2
CVSS 4.0 · Vendor: GitHub_M
Share

Severity by source

Vendor (GitHub_M) PRIMARY
8.2 HIGH
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vuln.today AI
5.9 MEDIUM

Network-accessible oracle with high complexity due to required adaptive query volume and specific reflective-service deployment; key recovery yields only confidentiality impact with no integrity or availability effect.

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
SUSE
5.9 MEDIUM
AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Primary rating from Vendor (GitHub_M).

CVSS VectorVendor: GitHub_M

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
X

Lifecycle Timeline

4
Patch available
Aug 03, 2026 - 22:17 EUVD
Source Code Evidence Fetched
Aug 03, 2026 - 22:06 vuln.today
Analysis Generated
Aug 03, 2026 - 22:06 vuln.today
CVE Published
Aug 03, 2026 - 21:16 cve.org
HIGH 8.2

Blast Radius

ecosystem impact
† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth
  • 153 pypi packages depend on cryptography (91 direct, 62 indirect)

Ecosystem-wide dependent count for version 44.0.0.

DescriptionCVE.org

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.

Articles & Coverage 2

News 3 New Python Vulnerabilities - 3 High Severity, 3 With POC Aug 04, 2026 News 3 New Python Vulnerabilities - 3 High Severity, 1 With POC Aug 03, 2026

AnalysisAI

PKCS#7 EnvelopedData decryption in the Python cryptography library (versions 44.0.0-49.x) leaks a Bleichenbacher oracle through four distinguishable error messages and timing side-channels during RSA PKCS#1 v1.5 key unwrapping, exposing the exact recovered plaintext length in one case. An attacker who can submit crafted EnvelopedData to an auto-decrypting service - such as an S/MIME gateway or mail filter that reflects outcomes at high volume - can adaptively recover the content-encryption key and decrypt intercepted messages. …

Unlock full vulnerability intelligence

  • Risk assessment & exploitation conditions
  • Attack chain visualization
  • Remediation with exact patch versions
  • Threat intelligence from 22 sources
  • Personal watchlist & email alerts
Continue with Google Continue with GitHub

Free forever · No credit card required

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access
Target S/MIME gateway or PKCS#7 auto-decrypt service
Delivery
Submit crafted EnvelopedData with manipulated encryptedKey at high volume
Exploit
Observe distinguishable error message or timing side-channel per failure case
Execution
Adapt subsequent encryptedKey values based on oracle responses
Persist
Accumulate sufficient query results to reconstruct content-encryption key
Impact
Decrypt intercepted EnvelopedData ciphertext
Sign in to reveal

Vulnerability AssessmentAI

Exploitation Exploitation requires all of the following to be simultaneously true: (1) a deployed service calls pkcs7_decrypt_der, pkcs7_decrypt_pem, or pkcs7_decrypt_smime on attacker-supplied EnvelopedData addressed to a victim certificate; (2) the service returns a distinguishable outcome to the attacker - different error messages, HTTP status codes, response bodies, or measurable timing - across the four decryption failure modes; (3) the attacker can submit high volumes of adaptive queries (thousands to millions) without being blocked by rate limiting or anomaly detection; and (4) for Case 1 (RSA invalid-padding branch), the service must link against OpenSSL 3.0/3.1, LibreSSL, or BoringSSL - installations using pyca's official pip wheels with OpenSSL 3.2+ are immune to Case 1 only. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment The CVSS 4.0 score of 8.2 with vector AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N accurately captures the asymmetry: confidentiality impact is high (key recovery enables plaintext recovery), but attack complexity is high and specific preconditions (AT:P) are required. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario An attacker who can deliver arbitrary S/MIME messages to a mail gateway running pyca/cryptography 44.0.0-49.x (linked against OpenSSL 3.0/3.1, LibreSSL, or BoringSSL) submits high volumes of crafted EnvelopedData with systematically manipulated encryptedKey fields targeting the gateway's recipient certificate. The gateway's distinguishable error responses - including the exact recovered key length leaked in case 2 - feed an adaptive Bleichenbacher query loop; over thousands to millions of queries the attacker recovers the content-encryption key and uses it to decrypt previously captured ciphertext. …
Remediation Upgrade pyca/cryptography to version 50.0.0, which applies the RFC 3218 indistinguishability fix: the expected content-encryption key length is resolved from the algorithm identifier before RSA decryption is attempted, and any failure (invalid RSA padding or recovered key of wrong length) substitutes a cryptographically random key of the correct size, so all failure paths perform identical work and produce identical error outputs. … Detailed patch versions, workarounds, and compensating controls in full report.
Sign in to read full assessment

Recommended ActionAI

Within 24 hours, audit production systems to identify all instances of Python cryptography versions 44.0.0 through 49.x, with priority on S/MIME gateways and mail filtering systems. …

Sign in for detailed remediation steps and compensating controls.

Threat intelligence, references, and detailed analysis are available after sign-in.

More in Python

View all
CVE-2025-24016 CRITICAL POC
9.9 Feb 10

Wazuh SIEM platform versions 4.4.0 through 4.9.0 contain an unsafe deserialization vulnerability in the DistributedAPI t
CVE-2025-27520 CRITICAL POC
9.8 Apr 04

BentoML version 1.4.2 and earlier contains an unauthenticated remote code execution vulnerability through insecure deser
CVE-2025-2945 CRITICAL POC
9.9 Apr 03

pgAdmin 4 contains critical remote code execution vulnerabilities in the Query Tool download and Cloud Deployment endpoi
CVE-2013-5093 MEDIUM POC
6.8 Sep 27

The renderLocalView function in render/views.py in graphite-web in Graphite 0.9.5 through 0.9.10 uses the pickle Python

CVE-2025-32375 CRITICAL POC
9.8 Apr 09

BentoML is a Python library for building online serving systems optimized for AI apps and model inference. Rated critica
CVE-2014-0224 HIGH POC
7.4 Jun 05

OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before 1.0.1h does not properly restrict processing of ChangeCiph
CVE-2024-21644 HIGH POC
7.5 Jan 08

pyLoad download manager version prior to 0.5.0b3.dev77 exposes the Flask SECRET_KEY through an unauthenticated endpoint.
CVE-2026-33017 CRITICAL POC
9.3 Mar 17

Langflow (a visual LLM pipeline builder) contains a critical unauthenticated code execution vulnerability (CVE-2026-3301
CVE-2017-9462 HIGH POC
8.8 Jun 06

In Mercurial before 4.1.3, "hg serve --stdio" allows remote authenticated users to launch the Python debugger, and conse
CVE-2026-39987 CRITICAL POC
9.3 Apr 08

Unauthenticated remote code execution in Marimo ≤0.20.4 allows attackers to execute arbitrary system commands via the `/
CVE-2024-21645 MEDIUM POC
5.3 Jan 08

pyLoad is the free and open-source Download Manager written in pure Python. Rated medium severity (CVSS 5.3), this vulne
CVE-2026-55255 HIGH POC
8.4 Jun 19

Cross-user flow execution in Langflow (< 1.9.1) lets any authenticated API-key holder run another user's flow by passing

Same weakness CWE-208 – Observable Timing Discrepancy

View all
CVE-2026-23519 CRITICAL POC
9.8
CVE-2024-47178 HIGH POC
8.7
CVE-2025-68621 HIGH POC
7.4
CVE-2024-7010 MEDIUM POC
5.9
CVE-2021-26314 MEDIUM POC
5.5
CVE-2026-23849 MEDIUM POC
5.3
CVE-2025-30344 MEDIUM POC
5.3
CVE-2024-45052 MEDIUM POC
5.3

Same technique Information Disclosure

View all
CVE-2019-2725 CRITICAL POC
9.8
CVE-2021-34523 CRITICAL POC
9.0
CVE-2013-2251 CRITICAL POC
9.8
CVE-2017-5638 CRITICAL POC
9.8
CVE-2025-24813 CRITICAL POC
9.8
CVE-2015-1701 HIGH POC
7.8
CVE-2017-0147 HIGH POC
7.5
CVE-2014-6324 HIGH POC
8.8

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Not-Affected
SUSE Linux Enterprise Desktop 15 SP7 Not-Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 Not-Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 Not-Affected
SUSE Linux Enterprise Micro 5.3 Not-Affected

Share

EUVD-2026-52446 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy