OpenSSL

CVE-2025-69418: Unauthenticated/unencrypted trailing bytes with low-level OCB function calls

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.1%

EPSS score, percentile 2.8 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

4.0 Medium

CVSS v3.1 base score, from CISA's enrichment of the record

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (6)

Which versions are affected?

Affected

from 3.6.0 to before 3.6.1
from 3.5.0 to before 3.5.5
from 3.4.0 to before 3.4.4
from 3.3.0 to before 3.3.6
from 3.0.0 to before 3.0.19
from 1.1.1 to before 1.1.1ze

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Advisories and patches

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

OpenSSL OpenSSL
Status	Versions
Affected	from 3.6.0 to before 3.6.1
Affected	from 3.5.0 to before 3.5.5
Affected	from 3.4.0 to before 3.4.4
Affected	from 3.3.0 to before 3.3.6
Affected	from 3.0.0 to before 3.0.19
Affected	from 1.1.1 to before 1.1.1ze

Versions not listed are: unaffected.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

Summary: CVE record, as of 29 Oct 2026.

CISA has not added CVE-2025-69418 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
The CVE record was published on 27 Jan 2026.
The CVE record carries a CVSS v3.1 base score of 4.0 (Medium), taken from CISA's enrichment of the record.
FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.1% (percentile 2.8), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
The credits in the CVE record name AISLE as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

Unauthenticated/unencrypted trailing bytes with low-level OCB function calls

Issue summary: When using the low-level OCB API directly with AES-NI or other hardware-accelerated code paths, inputs whose length is not a multiple of 16 bytes can leave the final partial block unencrypted and unauthenticated. Impact summary: The trailing 1-15 bytes of a message may be exposed in cleartext on encryption and are not covered by the authentication tag, allowing an attacker to read or tamper with those bytes without detection. The low-level OCB encrypt and decrypt routines in the hardware-accelerated stream path process full 16-byte blocks but do not advance the input/output pointers. The subsequent tail-handling code then operates on the original base pointers, effectively reprocessing the beginning of the buffer while leaving the actual trailing bytes unprocessed. The authentication checksum also excludes the true tail bytes. However, typical OpenSSL consumers using EVP are not affected because the higher-level EVP and provider OCB implementations split inputs so that full blocks and trailing partial blocks are processed in separate calls, avoiding the problematic code path. Additionally, TLS does not use OCB ciphersuites. The vulnerability only affects applications that call the low-level CRYPTO_ocb128_encrypt() or CRYPTO_ocb128_decrypt() functions directly with non-block-aligned lengths in a single call on hardware-accelerated builds. For these reasons the issue was assessed as Low severity. The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected by this issue, as OCB mode is not a FIPS-approved algorithm. OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are vulnerable to this issue. OpenSSL 1.0.2 is not affected by this issue.

Source: CVE List, as of 29 Oct 2026. About the data.

Weakness

CWE-325

CWE-325: Missing Cryptographic Step

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.

Timeline

Date	Event
27 Jan 2026	CVE record published
15 Oct 2026	CVE record last updated

Known exploited OpenSSL vulnerabilities

CVE-2014-0160: OpenSSL Information Disclosure Vulnerability (added 4 May 2022)