CVE-2026-7383

Publication date 9 June 2026

Last updated 18 June 2026

Ubuntu priority

Low

Why this priority?

Cvss 3 Severity Score

8.1 · High

Score breakdown

Description

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.

Read the notes from the security team

Why is this CVE low priority?

OpenSSL developers have rated this as being low severity

Learn more about Ubuntu priority

Status

Package Ubuntu Release Status
edk2 26.04 LTS resolute
Needs evaluation
25.10 questing
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
nodejs 26.04 LTS resolute
Not affected
25.10 questing
Not affected
24.04 LTS noble
Not affected
22.04 LTS jammy
Vulnerable
20.04 LTS focal
Not affected
18.04 LTS bionic
Needs evaluation
14.04 LTS trusty
Not affected
openssl 26.04 LTS resolute
Fixed 3.5.5-1ubuntu3.2
25.10 questing
Fixed 3.5.3-1ubuntu3.4
24.04 LTS noble
Fixed 3.0.13-0ubuntu3.11
22.04 LTS jammy
Fixed 3.0.2-0ubuntu1.25
20.04 LTS focal
Fixed 1.1.1f-1ubuntu2.24+esm4
18.04 LTS bionic
Fixed 1.1.1-1ubuntu2.1~18.04.23+esm9
16.04 LTS xenial
Fixed 1.0.2g-1ubuntu4.20+esm16
14.04 LTS trusty
Fixed 1.0.1f-1ubuntu2.27+esm14
openssl-fips 26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
openssl1.0 26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
18.04 LTS bionic
Fixed 1.0.2n-1ubuntu5.13+esm5

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Notes

mdeslaur

edk2 in jammy embeds OpenSSL 1.1.1j edk2 in noble embeds OpenSSL 3.0.9 edk2 in plucky embeds OpenSSL 3.4.0 edk2 in questing embeds OpenSSL 3.4.0 nodejs in jammy embeds OpenSSL 1.1.1m OpenSSL 4.0, 3.6, 3.5, 3.4, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue.

Severity score breakdown

CVSS version: CVSS v3.0

Base score 8.1 · High

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

Other references

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