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

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-9076— Out-of-Bounds Read in CMS Password-Based Decryption

Quick assessment

Affected
OpenSSL OpenSSL
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

OpenSSL是OpenSSL团队的一个开源的能够实现安全套接层（SSLv2/v3）和安全传输层（TLSv1）协议的通用加密库。该产品支持多种加密算法，包括对称密码、哈希算法、安全散列算法等。 OpenSSL存在缓冲区错误漏洞，该漏洞源于CMS密码解密处理中，攻击者选择的流模式KEK密码可触发kek_unwrap_key函数中的堆越界读取，可能导致应用程序崩溃，造成拒绝服务。

AI Predicted 5.5 Difficulty: Moderate EPSS 0.62% · P47

Affected Version Matrix 7

VendorProduct Version RangeStatus
OpenSSL OpenSSL 4.0.0< 4.0.1 affected
3.6.0< 3.6.3 affected
3.5.0< 3.5.7 affected
3.4.0< 3.4.6 affected
3.0.0< 3.0.21 affected
1.1.1< 1.1.1zh affected
1.0.2< 1.0.2zq affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-9076

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
Out-of-Bounds Read in CMS Password-Based Decryption
Source: CVE Program / CVE List V5
Vulnerability Description
Issue summary: When CMS password-based decryption (RFC 3211 / PWRI key unwrap) processes attacker-supplied CMS data, an attacker-chosen stream-mode KEK cipher can trigger a heap out-of-bounds read in kek_unwrap_key(). Impact summary: A heap buffer over-read may trigger a crash which leads to Denial of Service for an application if the input buffer ends at a memory page boundary and the following page is unmapped. There is no information disclosure as the over-read bytes are not revealed to the attacker. The key unwrapping function performs a check-byte test as specified in the RFC that reads 7 bytes from a heap allocation that is based on the wrapped key length from the message. There is a minimum length check based on the block length of the wrapping cipher. However the cipher is selected from an OID carried in the attacker's PWRI keyEncryptionAlgorithm with no requirement that the cipher be a block cipher. When an attacker selects a stream-mode cipher the guard will be ineffective and the allocated buffer containing the unwrapped key can be too small to fit the check-bytes specified in the RFC and a buffer over-read can happen. Applications calling CMS_decrypt() or CMS_decrypt_set1_password() (equivalently openssl cms -decrypt -pwri_password ...) on untrusted CMS data are vulnerable to this issue. No password knowledge is required: the over-read happens during the unwrap attempt before any authentication succeeds. The over-read is limited to a few bytes and is not written to output, so there is no information disclosure. Triggering a crash requires the allocation to border unmapped memory, which is unlikely with the normal allocator. The FIPS modules are not affected by this issue.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
跨界内存读
Source: CVE Program / CVE List V5
Vulnerability Title
OpenSSL 缓冲区错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
OpenSSL是OpenSSL团队的一个开源的能够实现安全套接层（SSLv2/v3）和安全传输层（TLSv1）协议的通用加密库。该产品支持多种加密算法，包括对称密码、哈希算法、安全散列算法等。 OpenSSL存在缓冲区错误漏洞，该漏洞源于CMS密码解密处理中，攻击者选择的流模式KEK密码可触发kek_unwrap_key函数中的堆越界读取，可能导致应用程序崩溃，造成拒绝服务。
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
OpenSSL OpenSSL 4.0.0 ~ 4.0.1 -

II. Public POCs for CVE-2026-9076

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-9076

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-9076 (5)

Vendor Advisories for CVE-2026-9076 (1)

Same Patch Batch · OpenSSL · 2026-06-09 · 18 CVEs total

CVE-2026-45447 Heap Use-After-Free in the PKCS7_verify() Function
CVE-2026-34183 Unbounded Memory Growth in the QUIC PATH_CHALLENGE Handler
CVE-2026-34181 PKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys
CVE-2026-34180 Heap Buffer Over-read in ASN.1 Content Parsing
CVE-2026-34182 CMS AuthEnvelopedData Processing May Accept Forged Messages
CVE-2026-35188 Double-free When Checking OCSP Stapled Response
CVE-2026-7383 Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion
CVE-2026-45446 Incorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes
CVE-2026-45445 AES-OCB IV Ignored on EVP_Cipher() Path
CVE-2026-42771 Possible Out of Bounds Read in X509_VERIFY_PARAM_set1_email()
CVE-2026-42768 Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt()
CVE-2026-42769 Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate
CVE-2026-42767 NULL Pointer Dereference in CRMF EncryptedValue Decryption
CVE-2026-42766 Possible NULL Dereference in Password-Based CMS Decryption
CVE-2026-42764 NULL Pointer Dereference in QUIC Server Initial Packet Handling
CVE-2026-42770 FFC-DH Peer Validation Uses Attacker-Supplied q
CVE-2026-42765 NULL Dereference in Certificate Verification with OCSP Checking

IV. Related Vulnerabilities

Same product: OpenSSL
Same vendor: OpenSSL
Same weakness: CWE-125

V. Comments for CVE-2026-9076

No comments yet

Leave a comment