---
schema_version: '1.0'
id: security-20260705-f52085
url: https://osv.dev/vulnerability/DEBIAN-CVE-2026-9076
url_hash: f5208509cc9e4088ef4d707100b797d01390da9e55732546cfce89fb05953048
canonical_url: https://osv.dev/vulnerability/DEBIAN-CVE-2026-9076
source: osv:debian
category: security/os
category_raw: cve/os
region: null
tags:
- cve
- DEBIAN-CVE-2026-9076
- severity:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- openssl
- Debian
lang: en
published_at: '2026-06-09T17:17:50Z'
fetched_at: '2026-07-05T15:34:34Z'
updated_at: '2026-07-05T15:37:03Z'
status: published
content_hash: d3ad06ff1d9014ccc47e947e9380d7e6aaacebaa78f2741daf39d309b13ea0e0
license_note: full
summary: '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 w'
summary_source: rss
summary_en: '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 w'
entities: []
key_facts: []
related: []
related_auto: []
title: DEBIAN-CVE-2026-9076 — openssl
---

# DEBIAN-CVE-2026-9076 — openssl

## TL;DR
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 w

## Key Points
- cve / DEBIAN-CVE-2026-9076 / severity:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H / openssl / Debian

## Details
**Severity:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
**Advisory:** DEBIAN-CVE-2026-9076

**Affected (your watchlist):**
- `Debian:openssl` 3.0.11-1~deb12u2 → no fixed version listed [rpi]

**Details:**
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.

**References:**
- https://security-tracker.debian.org/tracker/CVE-2026-9076

_Data: OSV.dev (upstream: debian) — https://osv.dev/vulnerability/DEBIAN-CVE-2026-9076_

## Source
元記事: [DEBIAN-CVE-2026-9076 — openssl](https://osv.dev/vulnerability/DEBIAN-CVE-2026-9076) — published 2026-06-09T17:17:50Z