Possible Out of Bounds Read in X509_VERIFY_PARAM_set1_email()
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 fixed, 6 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-125 and the CVSS impact.
Summary
Issue summary: When the X509_VERIFY_PARAM_set1_email is called by an application to validate a crafted e-mail address, such as during S/MIME message validation, an out of bounds read can happen. Impact summary: This out of bounds read will not directly exfiltrate the data read to the attacker so the most likely result is a crash and a Denial of Service. An internal helper function called from X509_VERIFY_PARAM_[set|add]_email() used a wrong length when validating the local part of an email address. This could cause the 64 octet limit on the local part of an email address to be not enforced, or cause an out of bound read and potentially a crash. The bug is reachable via S-MIME validation with a crafted From: address supplied in an email message that can potentially cause a crash. No FIPS modules are affected by this issue as the affected code is outside the OpenSSL FIPS module boundary.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA OpenSSL (OpenSSL) Fixed in 4.0.1
Red Hat 8 advisories
- RHSA-2026:67551 Released 2026-09-15 · Red Hat rating ImportantRed 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 ImportantRed 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 ImportantRed 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
Show 5 more Red Hat advisories
- RHSA-2026:62562 Released 2026-09-02 · Red Hat rating ImportantRed 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 ImportantRed 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 ImportantRed 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-2026:55543 Released 2026-08-17 · Red Hat rating ImportantRed 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 ImportantRed 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
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
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat Hardened Images | Fixed | RHSA-2026:42825, RHSA-2026:55543, RHSA-2026:59635, RHSA-2026:59641, RHSA-2026:62562, RHSA-2026:62563, RHSA-2026:62790, RHSA-2026:67551 |
Not affected: 5 products
- Red Hat Enterprise Linux 9
- Red Hat Hardened Images
- Red Hat JBoss Core Services
- Red Hat JBoss Web Server 6
- Red Hat JBoss Web Server 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-42771
- 2026-10-03 Alias added: GHSA-6fmj-jmjq-qcmg
References
Patch 1
Advisory 1
More Openssl vulnerabilities
- 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
Sources
- CVE-2026-42771 · CVE Program
- CVE-2026-42771 · NVD
- FIRST EPSS
- GHSA-6fmj-jmjq-qcmg · GitHub Advisory Database · CC BY 4.0
- CVE-2026-42771 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences