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NVD / CVE Program· CNA openssl

CVE-2026-75803: AEAD Forgeries with Empty Ciphertext When Using EVP_Cipher()

Noroxi assessment

Priority: Monitor (action score 36/100)

  • 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: 0.25% (FIRST EPSS).
  • 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 3.0.22, 3.4.7, 3.5.8.

Low priority for now. Upgrade to OpenSSL OpenSSL 3.0.22, 3.4.7, 3.5.8 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: ChaCha20-Poly1305 and AES-OCB decryption with an empty ciphertext can report success without verifying the supplied authentication tag when the operation is finalized by calling the EVP_Cipher() function. Impact summary: Applications calling EVP_Cipher() on an empty ciphertext and expecting the call to check the AEAD tag may accept forged messages. CWE: CWE-354 (Improper Validation of Integrity Check Value) Description: The EVP_Cipher() API call for AEAD ciphers behaves like a one shot encryption and decryption call. It also verifies the AEAD tag after the decryption operation. However for AES-OCB and ChaCha20-Poly1305 ciphers it skipped the AEAD tag verification when an empty ciphertext was passed to the function. The callers of this function might believe that a successful return indicates a valid AEAD tag for these ciphers, even when that has not truly been validated in this case. FIPS impact: no The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this CVE as the affected algorithms are not FIPS approved and thus not implemented in the FIPS module.

CriticalCVSS 9.1 · v3.1—No exploit Fix available
Published
Aug 25, 2026
Updated
Sep 11, 2026
EPSS
0.2% · 17th percentile

Report tools

JSON

Action score

36

Monitor

Low priority for now.

CVSS
36 / 40 · 9.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

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

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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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.

VendorProduct
opensslopenssl

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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 3.0.22
  • openssl openssl3.4.0 and later · before 3.4.7
  • openssl openssl3.5.0 and later · before 3.5.8
  • openssl openssl3.6.0 and later · before 3.6.4
  • openssl openssl4.0.0 and later · before 4.0.2

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

    • 4.0.0 and later · before 4.0.2affected · semver
    • 3.6.0 and later · before 3.6.4affected · semver
    • 3.5.0 and later · before 3.5.8affected · semver
    • 3.4.0 and later · before 3.4.7affected · semver
    • 3.0.0 and later · before 3.0.22affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:9opensslbefore 1:3.5.8-1.el9_81:3.5.8-1.el9_8
AlmaLinux:9openssl-develbefore 1:3.5.8-1.el9_81:3.5.8-1.el9_8
AlmaLinux:9openssl-libsbefore 1:3.5.8-1.el9_81:3.5.8-1.el9_8
AlmaLinux:9openssl-perlbefore 1:3.5.8-1.el9_81:3.5.8-1.el9_8
Alpine:v3.21opensslfrom 3.0.0 · before 3.3.7-r13.3.7-r1
Alpine:v3.22opensslfrom 3.0.0 · before 3.5.8-r03.5.8-r0
Debian:12opensslbefore 3.0.22-1~deb12u13.0.22-1~deb12u1
Debian:13opensslbefore 3.5.7-1~deb13u23.5.7-1~deb13u2
Debian:14opensslbefore 3.6.4-13.6.4-1
openSUSE:Leap 16.0openssl-3before 3.5.0-160000.10.13.5.0-160000.10.1
openSUSE:Tumbleweedopenssl-3before 3.5.3-8.13.5.3-8.1
Red Hat:hummingbird:1bootupdbefore 0:0.2.36-3.hum10:0.2.36-3.hum1
Red Hat:hummingbird:1chunkahbefore 0:0.6.0-3.hum10:0.6.0-3.hum1
Red Hat:hummingbird:1ruby3.3before 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.3-bundled-gemsbefore 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.3-default-gemsbefore 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.3-develbefore 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.3-docbefore 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.3-libsbefore 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.4before 0:3.4.10-31.7.hum10:3.4.10-31.7.hum1
Red Hat:hummingbird:1ruby3.4-bundled-gemsbefore 0:3.4.10-31.7.hum10:3.4.10-31.7.hum1
Red Hat:hummingbird:1ruby3.4-default-gemsbefore 0:3.4.10-31.7.hum10:3.4.10-31.7.hum1
Red Hat:hummingbird:1ruby3.4-develbefore 0:3.4.10-31.7.hum10:3.4.10-31.7.hum1
Red Hat:hummingbird:1ruby3.4-docbefore 0:3.4.10-31.7.hum10:3.4.10-31.7.hum1

+51

Same product

openssl: all records

Other 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 remKEV
    90Now
  • CVE-2021-3711SM2 Decryption Buffer Overflow
    65This 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-2026-63075Aug 25, 2026 · QUIC ACK-only Packet Retention Can Cause Memory Exhaustion
    30Monitor
  • ← EarlierCVE-2026-63076Aug 25, 2026 · Invalid Pointer Dereference in CMP Server via Crafted protectionAlg
    30Monitor
  • Later →CVE-2026-35189Sep 29, 2026 · Excessive Memory Allocation in Relative CRLDP Processing
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
OpenSSL OpenSSL3.0.22Vendor (CNA)
OpenSSL OpenSSL3.4.7Vendor (CNA)
OpenSSL OpenSSL3.5.8Vendor (CNA)
OpenSSL OpenSSL3.6.4Vendor (CNA)
OpenSSL OpenSSL4.0.2Vendor (CNA)
almalinux:openssl1:3.5.8-1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:openssl-devel1:3.5.8-1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:openssl-libs1:3.5.8-1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:openssl-perl1:3.5.8-1.el9_8 · AlmaLinux:9Package registry (OSV)
alpine:openssl3.3.7-r1 · Alpine:v3.21Package registry (OSV)
debian:openssl3.0.22-1~deb12u1 · Debian:12Package registry (OSV)
opensuse:openssl-33.5.3-8.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:bootupd0:0.2.36-3.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:chunkah0:0.6.0-3.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:ruby3.30:3.3.10-23.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:ruby3.3-bundled-gems0:3.3.10-23.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:ruby3.3-default-gems0:3.3.10-23.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:ruby3.3-devel0:3.3.10-23.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:ruby3.3-doc0:3.3.10-23.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:ruby3.3-libs0:3.3.10-23.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:rubygem3.3-bigdecimal0:3.1.5-23.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:rubygem3.3-bundler0:2.5.22-23.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:rubygem3.3-devel0:3.5.22-23.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:rust-bootupd0:0.2.36-3.hum1 · Red Hat:hummingbird:1Package registry (OSV)
suse:openssl-33.5.0-160000.10.1 · SUSE:Linux Micro 6.2Package 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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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.

Variant candidates

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

  • CVE-2026-3418277 days apartCMS AuthEnvelopedData Processing May Accept Forged Messages
    36Monitor
  • CVE-2026-3418177 days apartPKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys
    29Monitor

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
high · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
None

Weakness class (CWE)

CWE-354 · Improper Validation of Integrity Check Value

CVSS vector

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

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (5 more)

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

All records