---
schema_version: '1.0'
id: security-20260705-b82594
url: https://osv.dev/vulnerability/DEBIAN-CVE-2026-7383
url_hash: b825941ab29d67fa834ffd046b2377387f4af1fefabc058e68894dc48f811a85
canonical_url: https://osv.dev/vulnerability/DEBIAN-CVE-2026-7383
source: osv:debian
category: security/os
category_raw: cve/os
region: null
tags:
- cve
- DEBIAN-CVE-2026-7383
- severity:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/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: ab58512fa2bf46bd0d2bc29382fd65ebaee377b1e691511e3c842e6d47e9449f
license_note: full
summary: 'Issue summary: A signed integer overflow when sizing the destination buffer
  for Unicode output in ASN1_mbstring_ncopy() can lead to a heap buffer overflow.  Impact
  summary: A heap buffer overflow may lead to a crash or possibly attacker controlled
  code execution or other undefine'
summary_source: rss
summary_en: 'Issue summary: A signed integer overflow when sizing the destination
  buffer for Unicode output in ASN1_mbstring_ncopy() can lead to a heap buffer overflow.  Impact
  summary: A heap buffer overflow may lead to a crash or possibly attacker controlled
  code execution or other undefine'
entities: []
key_facts: []
related: []
related_auto: []
title: DEBIAN-CVE-2026-7383 — openssl
---

# DEBIAN-CVE-2026-7383 — openssl

## TL;DR
Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in ASN1_mbstring_ncopy() can lead to a heap buffer overflow.  Impact summary: A heap buffer overflow may lead to a crash or possibly attacker controlled code execution or other undefine

## Key Points
- cve / DEBIAN-CVE-2026-7383 / severity:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H / openssl / Debian

## Details
**Severity:** CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
**Advisory:** DEBIAN-CVE-2026-7383

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

**Details:**
Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in ASN1_mbstring_ncopy() can lead to a heap buffer overflow.  Impact summary: A heap buffer overflow may lead to a crash or possibly attacker controlled code execution or other undefined behaviour.  In ASN1_mbstring_copy() and ASN1_mbstring_ncopy() the destination size for Unicode output is computed in a signed int: by left shift of the input character count for BMPSTRING (UTF-16) and UNIVERSALSTRING (UTF-32), and by summing per-character byte counts for UTF8STRING. The calculation overflows when the input reaches around 2^30 characters. In the worst case (UNIVERSALSTRING at 2^30 characters) the size wraps to zero, OPENSSL_malloc(1) is called, and the subsequent character copy writes several gigabytes past the one-byte allocation.  X.509 certificate processing routes through ASN1_STRING_set_by_NID(), whose DIRSTRING_TYPE mask excludes UNIVERSALSTRING and whose per-NID size limits cap the input length; no network protocol or certificate-handling path in OpenSSL exercises the overflow. Triggering the bug requires an application that calls ASN1_mbstring_copy() or ASN1_mbstring_ncopy() directly, or registers a custom string type via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a gigabyte or more. For these reasons this issue was assigned Low severity.  The FIPS modules in 4.0, 3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

**References:**
- https://security-tracker.debian.org/tracker/CVE-2026-7383

_Data: OSV.dev (upstream: debian) — https://osv.dev/vulnerability/DEBIAN-CVE-2026-7383_

## Source
元記事: [DEBIAN-CVE-2026-7383 — openssl](https://osv.dev/vulnerability/DEBIAN-CVE-2026-7383) — published 2026-06-09T17:17:50Z