CVE-2026-42766: Possible NULL Dereference in Password-Based CMS Decryption
Noroxi assessment
Priority: Monitor (action score 23/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 1% (FIRST EPSS); higher than 64.8% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: OpenSSL OpenSSL 3.0.21, 3.4.6, 3.5.7; azl3 edk2 20240524git3e722403cd16-17 on Azure Linux 3.0 20240524git3e722403cd16-18; azl3 openssl 3.3.5-5 on Azure Linux 3.0 3.3.7-3.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to OpenSSL OpenSSL 3.0.21, 3.4.6, 3.5.7; azl3 edk2 20240524git3e722403cd16-17 on Azure Linux 3.0 20240524git3e722403cd16-18; azl3 openssl 3.3.5-5 on Azure Linux 3.0 3.3.7-3 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Issue summary: A specially crafted password-encrypted CMS message can trigger a NULL pointer dereference during CMS decryption. Impact summary: This NULL pointer dereference leads to an application crash and a Denial of Service. The CMS PasswordRecipientInfo.keyDerivationAlgorithm field is defined as OPTIONAL in the ASN.1 specification and may therefore be absent in specially crafted inputs. During the password-based CMS decryption the OpenSSL CMS implementation dereferences this field without first checking whether it was present. An attacker who supplies such a CMS message to an application performing password-based CMS decryption can trigger an application crash, leading to a Denial of Service. Applications that process password-encrypted CMS messages may be affected. 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.
- ALSA-2026:25237
- ALSA-2026:25239
- openSUSE-SU-2026:11023-1
- openSUSE-SU-2026:21005-1
- RHSA-2026:25237
- RHSA-2026:25239
- RHSA-2026:42825
- RHSA-2026:55543
- RHSA-2026:59635
- RHSA-2026:59641
- RHSA-2026:62562
- RHSA-2026:62563
- RHSA-2026:62790
- RHSA-2026:67551
- RLSA-2026:25237
- RLSA-2026:25239
- SUSE-SU-2026:22100-1
- SUSE-SU-2026:22132-1
- SUSE-SU-2026:22251-1
- SUSE-SU-2026:22315-1
- Published
- Jun 9, 2026
- Updated
- Jul 23, 2026
- EPSS
- 1.0% · 64th percentile
- CWE
- CWE-476
Report tools
Action score
23
Monitor
Low priority for now.
- CVSS
- 23 / 40 · 5.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.0%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Check your server's TLS configurationRun the SSL check
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| openssl | openssl | cpe:2.3:a:openssl:openssl |
Check your server's TLS configuration
The OpenSSL version can't be seen from outside; the free SSL checker tests your certificate, enabled TLS versions and weak ciphers. Confirm the version on your server with the package manager.
Run the SSL checkAffected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- openssl openssl1.0.2 and later · before 1.0.2zq
- openssl openssl1.1.1 and later · before 1.1.1zh
- openssl openssl3.0.0 and later · before 3.0.21
- openssl openssl3.4.0 and later · before 3.4.6
- openssl openssl3.5.0 and later · before 3.5.7
- openssl openssl3.6.0 and later · before 3.6.3
- openssl openssl4.0.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (openssl). Independent of NVD's CPE analysis and usually ahead of it.
OpenSSL OpenSSL
- 4.0.0 and later · before 4.0.1affected · semver
- 3.6.0 and later · before 3.6.3affected · semver
- 3.5.0 and later · before 3.5.7affected · semver
- 3.4.0 and later · before 3.4.6affected · semver
- 3.0.0 and later · before 3.0.21affected · semver
- 1.1.1 and later · before 1.1.1zhaffected
- 1.0.2 and later · before 1.0.2zqaffected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:10 | openssl | before 1:3.5.5-4.el10_2.alma.1 | 1:3.5.5-4.el10_2.alma.1 |
| AlmaLinux:10 | openssl-devel | before 1:3.5.5-4.el10_2.alma.1 | 1:3.5.5-4.el10_2.alma.1 |
| AlmaLinux:10 | openssl-libs | before 1:3.5.5-4.el10_2.alma.1 | 1:3.5.5-4.el10_2.alma.1 |
| AlmaLinux:10 | openssl-perl | before 1:3.5.5-4.el10_2.alma.1 | 1:3.5.5-4.el10_2.alma.1 |
| AlmaLinux:9 | openssl | before 1:3.5.5-4.el9_8 | 1:3.5.5-4.el9_8 |
| AlmaLinux:9 | openssl-devel | before 1:3.5.5-4.el9_8 | 1:3.5.5-4.el9_8 |
| AlmaLinux:9 | openssl-libs | before 1:3.5.5-4.el9_8 | 1:3.5.5-4.el9_8 |
| AlmaLinux:9 | openssl-perl | before 1:3.5.5-4.el9_8 | 1:3.5.5-4.el9_8 |
| Alpine:v3.21 | openssl | from 1.0.2 · before 3.3.7-r1 | 3.3.7-r1 |
| Alpine:v3.22 | openssl | from 1.0.2 · before 3.5.7-r0 | 3.5.7-r0 |
| Debian:12 | openssl | before 3.0.20-1~deb12u2 | 3.0.20-1~deb12u2 |
| Debian:13 | openssl | before 3.5.6-1~deb13u2 | 3.5.6-1~deb13u2 |
| Debian:14 | openssl | before 3.6.3-1 | 3.6.3-1 |
| openSUSE:Leap 16.0 | openssl-3 | before 3.5.0-160000.8.1 | 3.5.0-160000.8.1 |
| openSUSE:Tumbleweed | openssl-3 | before 3.5.3-6.1 | 3.5.3-6.1 |
| Red Hat:enterprise_linux:10.2 | openssl | before 1:3.5.5-4.el10_2 | 1:3.5.5-4.el10_2 |
| Red Hat:enterprise_linux:10.2 | openssl-debuginfo | before 1:3.5.5-4.el10_2 | 1:3.5.5-4.el10_2 |
| Red Hat:enterprise_linux:10.2 | openssl-debugsource | before 1:3.5.5-4.el10_2 | 1:3.5.5-4.el10_2 |
| Red Hat:enterprise_linux:10.2 | openssl-devel | before 1:3.5.5-4.el10_2 | 1:3.5.5-4.el10_2 |
| Red Hat:enterprise_linux:10.2 | openssl-libs | before 1:3.5.5-4.el10_2 | 1:3.5.5-4.el10_2 |
| Red Hat:enterprise_linux:10.2 | openssl-libs-debuginfo | before 1:3.5.5-4.el10_2 | 1:3.5.5-4.el10_2 |
| Red Hat:enterprise_linux:10.2 | openssl-perl | before 1:3.5.5-4.el10_2 | 1:3.5.5-4.el10_2 |
| Red Hat:enterprise_linux:9::appstream | openssl-debuginfo | before 1:3.5.5-4.el9_8 | 1:3.5.5-4.el9_8 |
| Red Hat:enterprise_linux:9::appstream | openssl-debugsource | before 1:3.5.5-4.el9_8 | 1:3.5.5-4.el9_8 |
+91
Same product
openssl: all recordsOther highest-scoring records for the same primary product.
- CVE-2014-0160The (1) TLS and (2) DTLS implementations in OpenSSL 1.0.1 before 1.0.1g do not properly handle Heartbeat Extension packets, which allows…KEV90Now
- CVE-2021-3711SM2 Decryption Buffer Overflow65This week
- CVE-2003-0545Double free vulnerability in OpenSSL 0.9.7 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code…65This week
Published before and after this one in the same product
- ← EarlierCVE-2026-42764Jun 9, 2026 · NULL Pointer Dereference in QUIC Server Initial Packet Handling30Monitor
- ← EarlierCVE-2026-42765Jun 9, 2026 · NULL Dereference in Certificate Verification with OCSP Checking30Monitor
- Later →CVE-2026-42767Jun 9, 2026 · NULL Pointer Dereference in CRMF EncryptedValue Decryption23Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| OpenSSL OpenSSL | 3.0.21 | Vendor (CNA) |
| OpenSSL OpenSSL | 3.4.6 | Vendor (CNA) |
| OpenSSL OpenSSL | 3.5.7 | Vendor (CNA) |
| OpenSSL OpenSSL | 3.6.3 | Vendor (CNA) |
| OpenSSL OpenSSL | 4.0.1 | Vendor (CNA) |
| azl3 edk2 20240524git3e722403cd16-17 on Azure Linux 3.0 | 20240524git3e722403cd16-18 · CBL-Mariner Releases | Microsoft (MSRC) |
| azl3 openssl 3.3.5-5 on Azure Linux 3.0 | 3.3.7-3 · CBL-Mariner Releases | Microsoft (MSRC) |
| almalinux:openssl | 1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:openssl-devel | 1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:openssl-libs | 1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10 | Package registry (OSV) |
| almalinux:openssl-perl | 1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10 | Package registry (OSV) |
| alpine:openssl | 3.3.7-r1 · Alpine:v3.21 | Package registry (OSV) |
| debian:openssl | 3.0.20-1~deb12u2 · Debian:12 | Package registry (OSV) |
| opensuse:openssl-3 | 3.5.3-6.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| red hat:chunkah | 0:0.6.0-3.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl | 1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:openssl-debuginfo | 1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:openssl-debugsource | 1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:openssl-devel | 1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:openssl-libs | 1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:openssl-libs-debuginfo | 1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:openssl-perl | 1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2 | Package registry (OSV) |
| red hat:openssl3 | 0:3.5.8-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:openssl3-devel | 0:3.5.8-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:python-cryptography | 0:50.0.0-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:python3-cryptography | 0:50.0.0-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| rocky linux:openssl | 1:3.5.5-4.el10_2 · Rocky Linux:10 | Package registry (OSV) |
| suse:openssl-1_0_0 | 1.0.2p-3.109.1 · SUSE:Linux Enterprise Server 12 SP5-LTSS | Package registry (OSV) |
| suse:openssl-1_1 | 1.1.1w-150700.11.22.1 · SUSE:Linux Enterprise Module for Basesystem 15 SP7 | Package registry (OSV) |
| suse:openssl-3 | 3.1.4-14.1 · SUSE:Linux Micro 6.0 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Mayank Jangidreporter
- Kushal Khemkareporter
- Hari Priandanareporter
- Bhabani Sankar Dasreporter
- Igor Ustinovremediation developer
- Qifan Zhang (Palo Alto Networks)reporter
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-427640 days apartNULL Pointer Dereference in QUIC Server Initial Packet Handling30Monitor
- CVE-2026-427650 days apartNULL Dereference in Certificate Verification with OCSP Checking30Monitor
- CVE-2026-2838863 days apartNULL Pointer Dereference When Processing a Delta CRL30Monitor
- CVE-2026-2838963 days apartPossible NULL Dereference When Processing CMS KeyAgreeRecipientInfo30Monitor
- CVE-2026-2839063 days apartPossible NULL Dereference When Processing CMS KeyTransportRecipientInfo30Monitor
- CVE-2026-1445777 days apartRPK Server Signature Algorithm Selection Can Dereference a Missing Certificate30Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0355 · Jun 10, 2026(OpenSSL Güvenlik Zafiyeti)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-476 · NULL Pointer DereferenceCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (5 more)Show less
- github.com/openssl/openssl/commit/12bc26ffb3a2be728c9b86e1cae277de5b33dfa4
- github.com/openssl/openssl/commit/3ff64913615d648cfbb6a6f1cf5529ae7ea829d7
- github.com/openssl/openssl/commit/ab52d88cb5374876d59aee3c91f9e4ccce2b7ce4
- github.com/openssl/openssl/commit/da26f368732b83e40e9d356fe61c3d3aaab6d2e8
- openssl-library.org/news/secadv/20260609.txt
Vendor advisories and official records. Exploit/PoC links are deliberately left out.