CVE-2026-7383: Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion

Published May 27, 2026
·
Updated

Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in ASN1mbstringncopy() can lead to a heap buffer overflow.

Other sources

Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion

Microsoft

Affected Software

11 affected componentsFixes available
OpenSSL OpenSSL
debian/openssl<=1.1.1w-0+deb11u1, <=1.1.1w-0+deb11u7, <=3.0.20-1~deb12u1, <=3.5.6-1~deb13u1, <=3.6.2-1
3.0.20-1~deb12u23.5.6-1~deb13u2
OpenSSL OpenSSL>=1.0.2<1.0.2zq
OpenSSL OpenSSL>=1.1.1<1.1.1zh
OpenSSL OpenSSL>=3.0.0<3.0.21
OpenSSL OpenSSL>=3.4.0<3.4.6
OpenSSL OpenSSL>=3.5.0<3.5.7
OpenSSL OpenSSL>=3.6.0<3.6.3
OpenSSL OpenSSL=4.0.0
Microsoft azl3 edk2 20240524git3e722403cd16-17<20240524git3e722403cd16-18
20240524git3e722403cd16-18
Microsoft azl3 openssl 3.3.5-5<3.3.7-3
3.3.7-3

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/openssl to a version that resolves this vulnerability.

    Fixed in 3.0.20-1~deb12u2Fixed in 3.5.6-1~deb13u2
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 20240524git3e722403cd16-18
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 3.3.7-3
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 1.0.2zq
  5. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 1.1.1zh
  6. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 3.0.21
  7. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 3.4.6
  8. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 3.5.7
  9. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 3.6.3
  10. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 4.0.1

Event History

May 27, 2026
Data Sourced
via Red Hat·01:10 PM
DescriptionSeverityAffected Software
Jun 9, 2026
CVE Published
via MITRE·04:03 PM
Data Sourced
via MITRE·04:03 PM
DescriptionWeakness
Data Sourced
via NVD·05:17 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·05:17 PM
RemedyAffected Software
Data Sourced
via Ubuntu·08:07 PM
RemedyDescriptionSeverityAffected Software
Jun 10, 2026
Data Sourced
via Debian·08:09 PM
DescriptionAffected Software
Data Sourced
via Launchpad·08:09 PM
Description
Jun 13, 2026
Data Sourced
via Microsoft·08:03 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·08:03 AM
Affected Software
Updated
via Microsoft·08:03 AM
DescriptionSeverity
Updated
via Microsoft·08:03 AM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What is the severity of CVE-2026-7383?

The severity of CVE-2026-7383 is rated as high with a CVSS score of 8.1.

2

How do I fix CVE-2026-7383?

To fix CVE-2026-7383, upgrade to the latest version of OpenSSL that contains security patches addressing this vulnerability.

3

What causes CVE-2026-7383?

CVE-2026-7383 is caused by a signed integer overflow when sizing the destination buffer for Unicode output in the ASN1_mbstring_ncopy() function.

4

What are the potential impacts of CVE-2026-7383?

The potential impacts of CVE-2026-7383 include a heap buffer overflow that can lead to memory corruption or code execution.

5

Which software is affected by CVE-2026-7383?

CVE-2026-7383 affects OpenSSL and specifically the ASN.1 multibyte string conversion functions.

Contact

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