NVD / CVE Program· CNA openssl

CVE-2026-31790: Incorrect Failure Handling in RSA KEM RSASVE Encapsulation

Noroxi assessment

Priority: Monitor (action score 30/100)

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 64.4% 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. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: OpenSSL OpenSSL 3.0.20, 3.3.7, 3.4.5; azl3 openssl 3.3.5-4 on Azure Linux 3.0 3.3.5-5.

Low priority for now. Upgrade to OpenSSL OpenSSL 3.0.20, 3.3.7, 3.4.5; azl3 openssl 3.3.5-4 on Azure Linux 3.0 3.3.5-5 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: Applications using RSASVE key encapsulation to establish a secret encryption key can send contents of an uninitialized memory buffer to a malicious peer. Impact summary: The uninitialized buffer might contain sensitive data from the previous execution of the application process which leads to sensitive data leakage to an attacker. RSA_public_encrypt() returns the number of bytes written on success and -1 on error. The affected code tests only whether the return value is non-zero. As a result, if RSA encryption fails, encapsulation can still return success to the caller, set the output lengths, and leave the caller to use the contents of the ciphertext buffer as if a valid KEM ciphertext had been produced. If applications use EVP_PKEY_encapsulate() with RSA/RSASVE on an attacker-supplied invalid RSA public key without first validating that key, then this may cause stale or uninitialized contents of the caller-provided ciphertext buffer to be disclosed to the attacker in place of the KEM ciphertext. As a workaround calling EVP_PKEY_public_check() or EVP_PKEY_public_check_quick() before EVP_PKEY_encapsulate() will mitigate the issue. The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.1 and 3.0 are affected by this issue.

HighCVSS 7.5 · v3.1—No exploit Fix available

Pre-auth

Published: Apr 7, 2026
Updated: Jul 24, 2026
EPSS: 1.0% · 64th percentile
CWE: CWE-754

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.0%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

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Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi 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.

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Affected 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

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Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

openssl openssl3.0.0 and later · before 3.0.20
openssl openssl3.3.0 and later · before 3.3.7
openssl openssl3.4.0 and later · before 3.4.5
openssl openssl3.5.0 and later · before 3.5.6
openssl openssl3.6.0 and later · before 3.6.2

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
- 3.6.0 and later · before 3.6.2affected · semver
- 3.5.0 and later · before 3.5.6affected · semver
- 3.4.0 and later · before 3.4.5affected · semver
- 3.3.0 and later · before 3.3.7affected · semver
- 3.0.0 and later · before 3.0.20affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
AlmaLinux:10	edk2-aarch64	before 20251114-5.el10_2.2	20251114-5.el10_2.2
AlmaLinux:10	edk2-ovmf	before 20251114-5.el10_2.2	20251114-5.el10_2.2
AlmaLinux:10	edk2-tools	before 20251114-5.el10_2.2	20251114-5.el10_2.2
AlmaLinux:10	edk2-tools-doc	before 20251114-5.el10_2.2	20251114-5.el10_2.2
AlmaLinux:10	openssl	before 1:3.5.5-2.el10_2.alma.1	1:3.5.5-2.el10_2.alma.1
AlmaLinux:10	openssl-devel	before 1:3.5.5-2.el10_2.alma.1	1:3.5.5-2.el10_2.alma.1
AlmaLinux:10	openssl-libs	before 1:3.5.5-2.el10_2.alma.1	1:3.5.5-2.el10_2.alma.1
AlmaLinux:10	openssl-perl	before 1:3.5.5-2.el10_2.alma.1	1:3.5.5-2.el10_2.alma.1
AlmaLinux:9	openssl	before 1:3.5.5-2.el9_8	1:3.5.5-2.el9_8
AlmaLinux:9	openssl-devel	before 1:3.5.5-2.el9_8	1:3.5.5-2.el9_8
AlmaLinux:9	openssl-libs	before 1:3.5.5-2.el9_8	1:3.5.5-2.el9_8
AlmaLinux:9	openssl-perl	before 1:3.5.5-2.el9_8	1:3.5.5-2.el9_8
Alpine:v3.20	openssl	from 3.0.0 · before 3.3.7-r0	3.3.7-r0
Alpine:v3.22	openssl	from 3.0.0 · before 3.5.6-r0	3.5.6-r0
Debian:12	openssl	before 3.0.19-1~deb12u2	3.0.19-1~deb12u2
Debian:13	openssl	before 3.5.5-1~deb13u2	3.5.5-1~deb13u2
Debian:14	openssl	before 3.6.2-1	3.6.2-1
openSUSE:Leap 15.6	openssl-1_0_0	before 1.0.2p-150000.3.105.1	1.0.2p-150000.3.105.1
openSUSE:Leap 15.6	openssl-3	before 3.1.4-150600.5.45.1	3.1.4-150600.5.45.1
openSUSE:Leap 16.0	openssl-3	before 3.5.0-160000.7.1	3.5.0-160000.7.1
openSUSE:Tumbleweed	openssl-3	before 3.5.3-4.1	3.5.3-4.1
Red Hat:enterprise_linux_eus:10.0	openssl	before 1:3.2.2-16.el10_0.7	1:3.2.2-16.el10_0.7
Red Hat:enterprise_linux_eus:10.0	openssl-debuginfo	before 1:3.2.2-16.el10_0.7	1:3.2.2-16.el10_0.7
Red Hat:enterprise_linux_eus:10.0	openssl-debugsource	before 1:3.2.2-16.el10_0.7	1:3.2.2-16.el10_0.7

+71

Same product

openssl: all records

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Published before and after this one in the same product

← EarlierCVE-2026-28390Apr 7, 2026 · Possible NULL Dereference When Processing CMS KeyTransportRecipientInfo
30Monitor
← EarlierCVE-2026-31789Apr 7, 2026 · Heap Buffer Overflow in Hexadecimal Conversion
39Monitor
Later →CVE-2026-34180Jun 9, 2026 · Heap Buffer Over-read in ASN.1 Content Parsing
30Monitor

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	3.0.20	Vendor (CNA)
OpenSSL OpenSSL	3.3.7	Vendor (CNA)
OpenSSL OpenSSL	3.4.5	Vendor (CNA)
OpenSSL OpenSSL	3.5.6	Vendor (CNA)
OpenSSL OpenSSL	3.6.2	Vendor (CNA)
azl3 openssl 3.3.5-4 on Azure Linux 3.0	3.3.5-5 · CBL-Mariner Releases	Microsoft (MSRC)
almalinux:edk2-aarch64	20251114-5.el10_2.2 · AlmaLinux:10	Package registry (OSV)
almalinux:edk2-ovmf	20251114-5.el10_2.2 · AlmaLinux:10	Package registry (OSV)
almalinux:edk2-tools	20251114-5.el10_2.2 · AlmaLinux:10	Package registry (OSV)
almalinux:edk2-tools-doc	20251114-5.el10_2.2 · AlmaLinux:10	Package registry (OSV)
almalinux:openssl	1:3.5.5-2.el10_2.alma.1 · AlmaLinux:10	Package registry (OSV)
almalinux:openssl-devel	1:3.5.5-2.el10_2.alma.1 · AlmaLinux:10	Package registry (OSV)
almalinux:openssl-libs	1:3.5.5-2.el10_2.alma.1 · AlmaLinux:10	Package registry (OSV)
almalinux:openssl-perl	1:3.5.5-2.el10_2.alma.1 · AlmaLinux:10	Package registry (OSV)
alpine:openssl	3.3.7-r0 · Alpine:v3.20	Package registry (OSV)
debian:openssl	3.0.19-1~deb12u2 · Debian:12	Package registry (OSV)
opensuse:openssl-1_0_0	1.0.2p-150000.3.105.1 · openSUSE:Leap 15.6	Package registry (OSV)
opensuse:openssl-3	3.1.4-150600.5.45.1 · openSUSE:Leap 15.6	Package registry (OSV)
red hat:openssl	1:3.5.5-2.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-debuginfo	1:3.5.5-2.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-debugsource	1:3.5.5-2.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-devel	1:3.5.5-2.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-fips-provider	0:3.0.7-11.el9_8 · Red Hat:enterprise_linux:9::baseos	Package registry (OSV)
red hat:openssl-fips-provider-debugsource	0:3.0.7-11.el9_0 · Red Hat:rhel_e4s:9.2::baseos	Package registry (OSV)
red hat:openssl-fips-provider-so	0:3.0.7-11.el9_8 · Red Hat:enterprise_linux:9::baseos	Package registry (OSV)
red hat:openssl-fips-provider-so-debuginfo	0:3.0.7-11.el9_8 · Red Hat:enterprise_linux:9::baseos	Package registry (OSV)
red hat:openssl-fips-provider-so-debugsource	0:3.0.7-11.el9_8 · Red Hat:enterprise_linux:9::baseos	Package registry (OSV)
red hat:openssl-libs	1:3.5.5-2.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-libs-debuginfo	1:3.5.5-2.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-perl	1:3.5.5-2.el10_2 · Red Hat:enterprise_linux:10.2	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 researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Nikola Pajkovskyremediation developer
Simo Sorce (Red Hat)reporter

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2025-6942070 days apartMissing ASN1_TYPE validation in TS_RESP_verify_response() function
30Monitor
CVE-2026-2279570 days apartMissing ASN1_TYPE validation in PKCS#12 parsing
22Monitor
CVE-2026-2279670 days apartASN1_TYPE Type Confusion in the PKCS7_digest_from_attributes() function
21Monitor

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).

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.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: none
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: None
Availability impact: None

Weakness class (CWE)

CWE-754 · Improper Check for Unusual or Exceptional Conditions

CVSS vector

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

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✗ → ✓Sep 28, 2026, 10:11 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/openssl/openssl/commit/001e01db3e996e13ffc72386fe79d03a6683b5ac

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records