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TI-2026-06486 Aliases CVE-2026-7383GHSA-w853-v86g-gv7j

Possible Heap Buffer Overflow in ASN.1 Multibyte String Conversion

Priority LOW 39CWE-787Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 11 fixed, 6 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.

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 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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00804 56th percentileScored 2026-11-07
Fix Partial OpenSSL (OpenSSL): 4.0.1, 3.6.3, 3.5.7 +4Red Hat: 22 advisoriesRed Hat: 11 fixed, 6 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
OpenSSLOpenSSL4.0.0 to before 4.0.1; 3.6.0 to before 3.6.3; 3.5.0 to before 3.5.7; 3.4.0 to before 3.4.6; 3.0.0 to before 3.0.21; 1.1.1 to before 1.1.1zh; 1.0.2 to before 1.0.2zq4.0.1, 3.6.3, 3.5.7, 3.4.6, 3.0.21, 1.1.1zh, 1.0.2zqPatch availableCNA
  • OpenSSL VendorOpenSSL Affected 4.0.0 to before 4.0.1; 3.6.0 to before 3.6.3; 3.5.0 to before 3.5.7; 3.4.0 to before 3.4.6; 3.0.0 to before 3.0.21; 1.1.1 to before 1.1.1zh; 1.0.2 to before 1.0.2zq Fixed in 4.0.1, 3.6.3, 3.5.7, 3.4.6, 3.0.21, 1.1.1zh, 1.0.2zq Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*1.0.2 to before 1.0.2zq; 1.1.1 to before 1.1.1zh; 3.0.0 to before 3.0.21; 3.4.0 to before 3.4.6; 3.5.0 to before 3.5.7; 3.6.0 to before 3.6.3VulnerableOpenSSL
cpe:2.3:a:openssl:openssl:4.0.0:-:*:*:*:*:*:*4.0.0VulnerableOpenSSL
  • cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* Versions 1.0.2 to before 1.0.2zq; 1.1.1 to before 1.1.1zh; 3.0.0 to before 3.0.21; 3.4.0 to before 3.4.6; 3.5.0 to before 3.5.7; 3.6.0 to before 3.6.3 Vulnerable ·OpenSSL
  • cpe:2.3:a:openssl:openssl:4.0.0:-:*:*:*:*:*:* Versions 4.0.0 Vulnerable ·OpenSSL

Remediation

  • Fix · CNA OpenSSL (OpenSSL) Fixed in 4.0.1, 3.6.3, 3.5.7, 3.4.6, 3.0.21, 1.1.1zh, 1.0.2zq

Red Hat 22 advisories

  • RHSA-2026:82888 Released 2026-10-14 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.17.2
    • Cert Manager support for Red Hat OpenShift release 1.17 registry.redhat.io/cert-manager/cert-manager-operator-bundle
  • RHSA-2026:82857 Released 2026-10-14 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.18.2
    • Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-operator-bundle
  • RHSA-2026:82372 Released 2026-10-13 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.18.2
    • Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
Show 19 more Red Hat advisories
  • RHSA-2026:82354 Released 2026-10-13 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.18.2
    • Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-istio-csr-rhel9
  • RHSA-2026:82347 Released 2026-10-13 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.18.2
    • Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/jetstack-cert-manager-acmesolver-rhel9, registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
  • RHSA-2026:82322 Released 2026-10-13 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.17.2
    • Cert Manager support for Red Hat OpenShift release 1.17 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
  • RHSA-2026:82304 Released 2026-10-13 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.17.2
    • Cert Manager support for Red Hat OpenShift release 1.17 registry.redhat.io/cert-manager/jetstack-cert-manager-acmesolver-rhel9, registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
  • RHSA-2026:72502 Released 2026-09-28 · Red Hat rating Important
    cert-manager Operator for Red Hat OpenShift 1.20.1
    • Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/cert-manager-trust-manager-rhel9
  • RHSA-2026:67551 Released 2026-09-15 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images bootupd-0.3.2-1.hum1@aarch64, bootupd-0.3.2-1.hum1@x86_64, rust-bootupd-0.3.2-1.hum1@src
  • RHSA-2026:62790 Released 2026-09-02 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images ruby3.4-3.4.10-31.7.hum1@aarch64, ruby3.4-3.4.10-31.7.hum1@src, ruby3.4-3.4.10-31.7.hum1@x86_64 +10
  • RHSA-2026:62563 Released 2026-09-02 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images ruby4.0-4.0.6-37.3.hum1@aarch64, ruby4.0-4.0.6-37.3.hum1@src, ruby4.0-4.0.6-37.3.hum1@x86_64 +46
  • RHSA-2026:62562 Released 2026-09-02 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images ruby3.3-3.3.10-23.6.hum1@aarch64, ruby3.3-3.3.10-23.6.hum1@src, ruby3.3-3.3.10-23.6.hum1@x86_64 +46
  • RHSA-2026:59641 Released 2026-08-25 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images openssl-1:3.5.8-0.1.hum1@aarch64, openssl-1:3.5.8-0.1.hum1@src, openssl-1:3.5.8-0.1.hum1@x86_64 +12
  • RHSA-2026:59635 Released 2026-08-25 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images openssl3-1:3.5.8-0.1.hum1@src, openssl3-devel-1:3.5.8-0.1.hum1@aarch64, openssl3-devel-1:3.5.8-0.1.hum1@x86_64 +4
  • RHSA-2026:58981 Released 2026-08-24 · Red Hat rating Critical
    Red Hat Update Infrastructure 5.3 Technology Preview security update
    • Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-tp-rhel9, registry.redhat.io/rhui5/installer-tp-rhel9, registry.redhat.io/rhui5/rhua-tp-rhel9
  • RHSA-2026:55543 Released 2026-08-17 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images python-cryptography-50.0.0-1.hum1@src, python3-cryptography-50.0.0-1.hum1@aarch64, python3-cryptography-50.0.0-1.hum1@x86_64
  • RHSA-2026:42825 Released 2026-07-21 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images chunkah-0.6.0-3.hum1@aarch64, chunkah-0.6.0-3.hum1@src, chunkah-0.6.0-3.hum1@x86_64
  • RHSA-2026:34102 Released 2026-07-01 · Red Hat rating Important
    Insights proxy Container Image
    • Red Hat Insights proxy 1.5 registry.redhat.io/insights-proxy/insights-proxy-container-rhel9
  • RHSA-2026:29197 Released 2026-06-24 · Red Hat rating Important
    A Subscription Management tool for finding and reporting Red Hat product usage
    • Red Hat Discovery 2 registry.redhat.io/discovery/discovery-server-rhel9, registry.redhat.io/discovery/discovery-ui-rhel9
  • RHSA-2026:26319 Released 2026-06-16 · Red Hat rating Important
    Red Hat Update Infrastructure 5.2 security update
    • Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9, registry.redhat.io/rhui5/installer-rhel9 +1
  • RHSA-2026:25239 Released 2026-06-11 · Red Hat rating Important
    openssl security update
    • Red Hat Enterprise Linux AppStream (v. 9) openssl-devel-1:3.5.5-4.el9_8, openssl-perl-1:3.5.5-4.el9_8
    • Red Hat Enterprise Linux BaseOS (v. 9) openssl-1:3.5.5-4.el9_8, openssl-libs-1:3.5.5-4.el9_8
  • RHSA-2026:25237 Released 2026-06-11 · Red Hat rating Important
    openssl security update
    • Red Hat Enterprise Linux AppStream (v. 10) openssl-devel-1:3.5.5-4.el10_2, openssl-perl-1:3.5.5-4.el10_2
    • Red Hat Enterprise Linux BaseOS (v. 10) openssl-1:3.5.5-4.el10_2, openssl-libs-1:3.5.5-4.el10_2

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    OpenSSL — openssl-library.org/news/secadv/20260609.txt

    18 records Highest priority Priority MEDIUM 6 MEDIUM, 12 LOW

    Other records, highest priority first

    • TI-2026-33226 Heap Use-After-Free in the PKCS7_verify() FunctionPriority MEDIUM 47
    • TI-2026-26479 CMS AuthEnvelopedData Processing May Accept Forged MessagesPriority MEDIUM 47
    • TI-2026-30987 NULL Pointer Dereference in QUIC Server Initial Packet HandlingPriority MEDIUM 41
    Show all 18 records → Advisory →

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 6AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 7AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Cert Manager support for Red Hat OpenShift release 1.17Fixed RHSA-2026:82304, RHSA-2026:82322, RHSA-2026:82888
Cert Manager support for Red Hat OpenShift release 1.18Fixed RHSA-2026:82347, RHSA-2026:82354, RHSA-2026:82372, RHSA-2026:82857
Cert Manager support for Red Hat OpenShift release 1.20Fixed RHSA-2026:72502
Red Hat Discovery 2Fixed RHSA-2026:29197
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:25237
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:25239
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:25237
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:25239
Red Hat Hardened ImagesFixed RHSA-2026:42825, RHSA-2026:55543, RHSA-2026:59635, RHSA-2026:59641, RHSA-2026:62562, RHSA-2026:62563, RHSA-2026:62790, RHSA-2026:67551
Red Hat Insights proxy 1.5Fixed RHSA-2026:34102
Red Hat Update Infrastructure 5Fixed RHSA-2026:26319, RHSA-2026:58981
Not affected: 5 products
  • Red Hat Hardened Images
  • Red Hat JBoss Core Services
  • Red Hat JBoss Web Server 6
  • Red Hat JBoss Web Server 7
  • Red Hat Update Infrastructure 5

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-7383
  2. 2026-10-03 Alias added: GHSA-w853-v86g-gv7j
  3. 2026-10-14 Fix available: RHSA-2026:82304 · Red Hat
  4. 2026-10-14 Fix available: RHSA-2026:82322 · Red Hat
  5. 2026-10-14 Fix available: RHSA-2026:82372 · Red Hat
  6. 2026-10-14 Fix available: RHSA-2026:82354 · Red Hat
  7. 2026-10-14 Fix available: RHSA-2026:82347 · Red Hat
  8. 2026-10-15 Fix available: RHSA-2026:82857 · Red Hat
  9. 2026-10-15 Fix available: RHSA-2026:82888 · Red Hat
  10. 2026-10-16 Fix available: Cert Manager support for Red Hat OpenShift release 1.17, Cert Manager support for Red Hat OpenShift release 1.18 · Red Hat

References

Patch 5

Advisory 1

  • TI-2022-01915 The c_rehash script allows command injection CVSS 3.1CRITICAL 9.8
  • TI-2021-02645 SM2 Decryption Buffer Overflow CVSS 3.1CRITICAL 9.8
  • TI-2009-03392 The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft… CVSS 3.1CRITICAL 9.8
  • TI-2022-01176 The c_rehash script allows command injection CVSS 3.1CRITICAL 9.8
  • TI-2014-00154 The (1) TLS and (2) DTLS implementations in OpenSSL 1.0.1 before 1.0.1g do not properly… KEVCVSS 3.1HIGH 7.5
  • TI-2025-14107 Stack buffer overflow in CMS (Auth)EnvelopedData parsing CVSS 3.1HIGH 8.8
See all 312 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences