Issue summary: Writing large, newline-free data into a BIO chain using the
line-buffering filter where the next BIO performs short writes can trigger
a heap-based out-of-bounds write.
Impact summary: This out-of-bounds write can cause memory corruption which
typically results in a crash, leading to Denial of Service for an application.
The line-buffering BIO filter (BIO_f_linebuffer) is not used by default in
TLS/SSL data paths. In OpenSSL command-line applications, it is typically
only pushed onto stdout/stderr on VMS systems. Third-party applications that
explicitly use this filter with a BIO chain that can short-write and that
write large, newline-free data influenced by an attacker would be affected.
However, the circumstances where this could happen are unlikely to be under
attacker control, and BIO_f_linebuffer is unlikely to be handling non-curated
data controlled by an attacker. For that reason the issue was assessed as
Low severity.
The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue,
as the BIO implementation is outside the OpenSSL FIPS module boundary.
OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue.
Metrics
Affected Vendors & Products
References
History
Mon, 02 Feb 2026 18:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| CPEs | cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* |
Thu, 29 Jan 2026 15:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Wed, 28 Jan 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Tue, 27 Jan 2026 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Openssl
Openssl openssl |
|
| Vendors & Products |
Openssl
Openssl openssl |
Tue, 27 Jan 2026 16:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Issue summary: Writing large, newline-free data into a BIO chain using the line-buffering filter where the next BIO performs short writes can trigger a heap-based out-of-bounds write. Impact summary: This out-of-bounds write can cause memory corruption which typically results in a crash, leading to Denial of Service for an application. The line-buffering BIO filter (BIO_f_linebuffer) is not used by default in TLS/SSL data paths. In OpenSSL command-line applications, it is typically only pushed onto stdout/stderr on VMS systems. Third-party applications that explicitly use this filter with a BIO chain that can short-write and that write large, newline-free data influenced by an attacker would be affected. However, the circumstances where this could happen are unlikely to be under attacker control, and BIO_f_linebuffer is unlikely to be handling non-curated data controlled by an attacker. For that reason the issue was assessed as Low severity. The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the BIO implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue. | |
| Title | Heap out-of-bounds write in BIO_f_linebuffer on short writes | |
| Weaknesses | CWE-787 | |
| References |
|
|
Status: PUBLISHED
Assigner: openssl
Published: 2026-01-27T16:01:23.181Z
Updated: 2026-01-29T15:06:04.443Z
Reserved: 2025-12-16T09:20:53.257Z
Link: CVE-2025-68160
Updated: 2026-01-29T15:05:45.180Z
Status : Analyzed
Published: 2026-01-27T16:16:15.900
Modified: 2026-02-02T18:36:57.727
Link: CVE-2025-68160
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