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TI-2026-45027 Aliases CVE-2026-63073GHSA-826x-qg76-xqjx

Untrusted Sender DN Used as Format String in CMP Response Validation

Priority MEDIUM 51CWE-134Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 7 fixed, 7 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-134 and the CVSS impact.

Summary

Issue summary: OpenSSL CMP response validation passed an unexpected response sender distinguished name directly as the format string to `ERR_raise_data()`. Impact summary: A malicious or intercepted CMP endpoint can crash a CMP client that enforces an expected sender or uses a pinned server certificate whose subject becomes the default expected sender. CWE: CWE-134 (Use of Externally-Controlled Format String) Description: When validating a received CMP message, ossl_cmp_msg_check_update() converts the peer-supplied sender distinguished name with X509_NAME_oneline() and passes it directly as the format argument to ERR_raise_data(). Percent characters survive the conversion, so a sender DN such as "CN=%s%n" reaches BIO_vsnprintf() as an attacker-controlled format string with no matching variadic arguments. This path is only reached when the caller configures an expected sender or pins a server certificate, which is the normal configuration for a CMP client validating server responses. Since the attacker controls the format string but none of the variadic arguments, such specifiers as %s and %n dereference or write through unrelated stack contents and crash the client. The reliable consequence is a denial of service, when the response comes from a malicious or intercepted CMP endpoint. There is no controlled memory write, arbitrary-address read, or reliable path to remote code execution. FIPS impact: no No FIPS modules are affected by this issue, as the CMP protocol implementation is outside the OpenSSL FIPS module boundary.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01159 67th percentileScored 2026-11-07
Fix Partial OpenSSL (OpenSSL): 4.0.2, 3.6.4, 3.5.8 +1Red Hat: 12 advisoriesRed Hat: 7 fixed, 7 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
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 4.0.2; 3.6.0 to before 3.6.4; 3.5.0 to before 3.5.8; 3.4.0 to before 3.4.74.0.2, 3.6.4, 3.5.8, 3.4.7Patch availableCNA
  • OpenSSL VendorOpenSSL Affected 4.0.0 to before 4.0.2; 3.6.0 to before 3.6.4; 3.5.0 to before 3.5.8; 3.4.0 to before 3.4.7 Fixed in 4.0.2, 3.6.4, 3.5.8, 3.4.7 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*3.4.0 to before 3.4.7; 3.5.0 to before 3.5.8; 3.6.0 to before 3.6.4; 4.0.0 to before 4.0.2VulnerableOpenSSL
  • cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* Versions 3.4.0 to before 3.4.7; 3.5.0 to before 3.5.8; 3.6.0 to before 3.6.4; 4.0.0 to before 4.0.2 Vulnerable ·OpenSSL

Remediation

  • Fix · CNA OpenSSL (OpenSSL) Fixed in 4.0.2, 3.6.4, 3.5.8, 3.4.7

Red Hat 12 advisories

  • RHSA-2026:72476 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-operator-rhel9
  • RHSA-2026:72475 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-istio-csr-rhel9
  • RHSA-2026:72470 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/jetstack-cert-manager-acmesolver-rhel9, registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
Show 9 more Red Hat advisories
  • RHSA-2026:72399 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-operator-rhel9
  • RHSA-2026:72395 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-istio-csr-rhel9
  • RHSA-2026:72394 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/jetstack-cert-manager-rhel9
  • RHSA-2026:71603 Released 2026-09-24 · Red Hat rating Important
    Red Hat Update Infrastructure 5.3 security update
    • Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-rhel9, registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9 +2
  • RHSA-2026:67956 Released 2026-09-16 · Red Hat rating Important
    Red Hat Update Infrastructure 5.3 security update
    • Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-rhel9, registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9 +2
  • RHSA-2026:67165 Released 2026-09-14 · Red Hat rating Important
    openssl security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) openssl-devel-1:3.5.8-1.el9_8, openssl-perl-1:3.5.8-1.el9_8
    • Red Hat Enterprise Linux BaseOS (v. 9) openssl-1:3.5.8-1.el9_8, openssl-libs-1:3.5.8-1.el9_8
  • RHSA-2026:67154 Released 2026-09-14 · Red Hat rating Important
    openssl security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) openssl-devel-1:3.5.8-1.el10_2, openssl-perl-1:3.5.8-1.el10_2
    • Red Hat Enterprise Linux BaseOS (v. 10) openssl-1:3.5.8-1.el10_2, openssl-libs-1:3.5.8-1.el10_2
  • 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

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/20260825.txt

    9 records Highest priority Priority MEDIUM 8 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-53058 AEAD Forgeries with Empty Ciphertext When Using EVP_Cipher()Priority MEDIUM 47
    • TI-2026-45030 Invalid Pointer Dereference in CMP Server via Crafted protectionAlgPriority MEDIUM 42
    • TI-2026-15397 QUIC Server May Trigger Double Free When Processing INITIAL PacketPriority MEDIUM 42
    Show all 9 records → Advisory →

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Developer Hub 1AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat JBoss Core ServicesAffectedNo fix yet: Fix deferred
Red Hat JBoss Web Server 6AffectedNo fix yet: Fix deferred
Red Hat JBoss Web Server 7AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Cert Manager support for Red Hat OpenShift release 1.20Fixed RHSA-2026:72394, RHSA-2026:72395, RHSA-2026:72399, RHSA-2026:72470, RHSA-2026:72475, RHSA-2026:72476
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:67154
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:67165
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:67154
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:67165
Red Hat Hardened ImagesFixed RHSA-2026:59635, RHSA-2026:59641
Red Hat Update Infrastructure 5Fixed RHSA-2026:67956, RHSA-2026:71603
Not affected: 12 products
  • Cert Manager support for Red Hat OpenShift release 1.20
  • Red Hat Enterprise Linux 10
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9
  • Red Hat Hardened Images
  • Red Hat OpenShift AI (RHOAI)
  • Red Hat OpenShift Container Platform 4
  • Red Hat Satellite 6
  • Red Hat Satellite Client
  • Red Hat Update Infrastructure 5

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-63073
  2. 2026-10-03 Alias added: GHSA-826x-qg76-xqjx
  3. 2026-10-27 Affected versions changed · Red Hat
  4. 2026-10-30 Affected versions changed · Red Hat
  5. 2026-11-07 Affected versions changed · Red Hat

References

Patch 4

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