Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-69249— python-cryptography: Duplicate self-signed intermediates can cause exponential path-building

Quick assessment

Affected
pyca cryptography
Exploitation
Public or AI PoC available; prioritize validation
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Python Cryptographic Authority cryptography是Python Cryptographic Authority组织开源的一款密码学工具库。 pyca cryptography 49.0.0之前版本存在资源管理错误漏洞，该漏洞源于解析无效证书链时递归处理重复的自签名证书，未对已分析候选去重，导致计算量指数级增长，可能造成资源耗尽拒绝服务。

CVSS 8.7 · High EPSS 0.25% · P15

Affected Version Matrix 1

VendorProduct Version RangeStatus
pyca cryptography >= 42.0.0, < 49.0.0 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-69249

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
python-cryptography: Duplicate self-signed intermediates can cause exponential path-building
Source: CVE Program / CVE List V5
Vulnerability Description
python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 42.0.0 through 48.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource exhaustion denial of service attack. The core issue arises in the recursive nature of build_chain_inner, which does not de-duplicate against previously analyzed candidates. As the correctness of validation is not affected, the integrity of a system cannot be compromised through this vector, only its availability. This issue is fixed in 49.0.0.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
未加控制的资源消耗(资源穷尽)
Source: CVE Program / CVE List V5
Vulnerability Title
pyca cryptography 资源管理错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Python Cryptographic Authority cryptography是Python Cryptographic Authority组织开源的一款密码学工具库。 pyca cryptography 49.0.0之前版本存在资源管理错误漏洞，该漏洞源于解析无效证书链时递归处理重复的自签名证书，未对已分析候选去重，导致计算量指数级增长，可能造成资源耗尽拒绝服务。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
pyca cryptography >= 42.0.0, < 49.0.0 -

II. Public POCs for CVE-2026-69249

# POC Description Source Link Shenlong Link
AI-Generated POC Premium
Qwen3.6-35B-A3B · 12325 chars
Pro+ exclusive includes:
Vulnerability reproduction recording (real sandbox build + trigger, exclusive)
In-depth vulnerability mechanism
Trigger conditions & impact
Full executable POC code
Exploit chain & mitigation
POC zip download
100+ AI POC generations per month

III. Intelligence Information for CVE-2026-69249

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-69249 (1)

Vendor Advisories for CVE-2026-69249 (2)

Same Patch Batch · pyca · 2026-08-03 · 3 CVEs total

CVE-2026-69247 8.2 HIGH cryptography: PKCS#7 EnvelopedData decryption exposes a Bleichenbacher oracle through dist
CVE-2026-69248 6.9 MEDIUM python-cryptography verifier accepts wildcard DNS names allowing escape from permittedSubt

IV. Related Vulnerabilities

Same product: cryptography
Same vendor: pyca
Same weakness: CWE-400

V. Comments for CVE-2026-69249

No comments yet

Leave a comment