Openssl: >> Openssl Security Vulnerabilities
Issue Summary: An error in the callback used to verify the certificate
provided in a Root CA key update Certificate Management Protocol (CMP)
message response rendered the certificate validation ineffectual, which
could lead to escalation of credentials from the Registration Authority (RA)
level to the root Certification Authority (root CA) level.
Impact Summary: The Registration Autority could replace the root CA
certificate for the CMP clients with an arbitrary root CA certificate.
One of the parts of the Certificate Management Protocol (CMP), specified in
RFC 9810, is Root Certification Authority (root CA) key Rollover,
which is sent by the server in a message with type 'id-it-rootCaKeyUpdate'.
As part of these messages, 'newWithOld' certificate, the new root CA
certificate signed with the old root CA key, is provided, and verifying its
signature is crucial for transferring the trust from the old CA key to the
new one.
The 'id-it-rootCaKeyUpdate' messages are expected to be processed with
OSSL_CMP_get1_rootCaKeyUpdate(), that is expected to verify the 'newWithOld'
certificate. A typo in the certificate chain building code led to adding
an incorrect certificate ('newWithOld' instead of 'oldRoot') to the
certificate chain, rendering the certificate verification process ineffectual
(only the issuer name and the algorithm OIDs were verified by other parts
of the verification code).
An attacker who already has credentials that satisfy the CMP message
protection checks can generate a new key pair and use a crafted self-signed
certificate in its 'id-it-rootCaKeyUpdate' CMP messages which affected CMP
clients would accept as a new trust anchor.
Significant preconditions for the attack (having valid RA-level credentials)
are the reason the issue was assigned Low severity.
The FIPS modules are not affected by this issue, as the affected code is
outside the OpenSSL FIPS module boundary.
CVSS Score
5.3
EPSS Score
0.002
Published
2026-06-09
Issue summary: When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42)
peer key, the peer key is not properly checked for the subgroup membership.
Impact summary: A malicious peer which presents an X9.42 key carrying the
victim's p and g parameters, a forged q = r (a small prime factor of the
cofactor (p−1)/q_local), and a public value Y of order r can recover the
victim's private key after a small number of key exchange attempts.
When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the
subgroup membership check Y^q ≡ 1 (mod p) is performed using the peer's
own q parameter, not the local key's q. The peer's domain parameters are
then matched against the domain parameters of the private key, but the value
of q is not compared.
A malicious peer who presents an X9.42 key carrying the victim's p, g,
a forged q = r (a small prime factor of the cofactor), and a public
value Y of order r passes all checks. The shared secret then takes only
r distinct values, leaking priv mod r. Repeating for each small-prime
factor of the cofactor and combining via CRT recovers the full private
key (Lim–Lee / small-subgroup-confinement attack).
The realistic attack surface is narrow: principally CMP deployments with
long-lived RA/CA DHX keys and bespoke enterprise or government applications
using X9.42 DHX static keys with interactive protocols and therefore this
issue was assigned Low severity.
The FIPS modules in 4.0, 3.6, 3.5, 3.4, 3.1.2 and 3.0 are affected by this
issue.
CVSS Score
3.7
EPSS Score
0.005
Published
2026-06-09
Issue summary: When the X509_VERIFY_PARAM_set1_email is called by an
application to validate a crafted e-mail address, such as during S/MIME
message validation, an out of bounds read can happen.
Impact summary: This out of bounds read will not directly exfiltrate
the data read to the attacker so the most likely result is a crash and
a Denial of Service.
An internal helper function called from X509_VERIFY_PARAM_[set|add]_email()
used a wrong length when validating the local part of an email address.
This could cause the 64 octet limit on the local part of an email address
to be not enforced, or cause an out of bound read and potentially a crash.
The bug is reachable via S-MIME validation with a crafted From: address
supplied in an email message that can potentially cause a crash.
No FIPS modules are affected by this issue as the affected code is outside
the OpenSSL FIPS module boundary.
CVSS Score
6.2
EPSS Score
0.002
Published
2026-06-09
Issue summary: Receiving a QUIC initial packet with an invalid token may
trigger a NULL pointer dereference in the OpenSSL QUIC server with
address validation disabled.
Impact summary: NULL pointer dereference typically causes abnormal termination
of the affected QUIC server process and a Denial of Service.
If the address validation is disabled in the OpenSSL QUIC server
implementation, an attacker can crash the server by sending an initial
packet with an invalid or expired token.
By default, the client address validation is enabled in the OpenSSL QUIC server
implementation, which makes the default configuration not vulnerable
to this issue. However if the SSL_LISTENER_FLAG_NO_VALIDATE is used with
the SSL_new_listener() call, the address validation is disabled making the
vulnerable code reachable.
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.
CVSS Score
7.5
EPSS Score
0.008
Published
2026-06-09
Issue summary: When a partial-chain certificate verification is enabled
together with OCSP response checking for the whole chain, a NULL dereference
will happen if the verified chain does not have a self-signed trusted anchor,
crashing the process.
Impact summary: A NULL pointer dereference can trigger a crash which leads to a
Denial of Service for an application.
When performing OCSP response checking for certificates in the verification
chain, the code always tries to access the next certificate as the issuer.
There is a check for a self-signed certificate. However with the partial
chain verification enabled when the chain does not have a self-signed trusted
anchor, the issuer will be NULL for the last certificate in the chain. A NULL
pointer dereference then happens.
This issue affects only applications which enable both OCSP verification
of the certificate chain (X509_V_FLAG_OCSP_RESP_CHECK_ALL) and partial
chain verification (X509_V_FLAG_PARTIAL_CHAIN) in the certificate
verification. Both flags are disabled by default. For that reason, we have
assigned Low severity to the issue.
No FIPS modules are affected by this issue as the affected code is outside
the OpenSSL FIPS module boundary.
CVSS Score
7.5
EPSS Score
0.005
Published
2026-06-09
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.
CVSS Score
5.9
EPSS Score
0.011
Published
2026-06-09
Issue summary: Remote peer may exhaust heap memory of the QUIC
server or client by flooding it with packets containing PATH_CHALLENGE
frames.
Impact summary: A malicious remote peer can cause an unbounded
memory allocation which can lead to an abnormal termination of the
application acting as a QUIC client or server and a Denial of Service.
A remote peer may exhaust heap memory by flooding the local
QUIC stack with PATH_CHALLENGE frames. The local QUIC stack
allocates a PATH_RESPONSE frame for every PATH_CHALLENGE it receives.
The allocated PATH_RESPONSE frame gets freed only when the remote
peer acknowledges reception of the PATH_RESPONSE frame which will
not be done by a malicious peer.
The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by
this issue. The QUIC stack is outside of OpenSSL FIPS module
boundary.
CVSS Score
7.5
EPSS Score
0.01
Published
2026-06-09
Issue summary: A malicious server can exploit TLS OCSP stapling by delivering
a crafted response through the status_request extension, triggering a
double-free in the client's certificate verification path.
Impact summary: Successful exploitation allows an attacker to corrupt heap
memory via a double-free, potentially leading to a Denial of Service or
possibly an attacker controlled code execution or other undefined behavior.
If OCSP stapling is enabled and the TLS client connects to a malicious server,
a crafted OCSP stapled response can trigger a double free in the TLS client
when the stapled response is checked.
The OCSP stapling is not enabled by default. Reliable code execution
through a double-free is technically complex and highly environment-dependent
but the Denial of Service impact is straightforward to achieve, warranting
Moderate severity.
No FIPS modules are affected by this issue as the affected code is outside
the OpenSSL FIPS module boundary.
CVSS Score
5.0
EPSS Score
0.002
Published
2026-06-09
Issue summary: Parsing a crafted DER-encoded ASN.1 structure with a primitive
element whose content exceeds 2 gigabytes in length may cause a heap buffer
over-read on 64-bit Unix and Unix-like platforms.
Impact summary: The heap buffer over-read may crash the application (Denial of
Service) or to load into the decoded ASN.1 object contents of memory beyond the
end of the input buffer. More typically such ASN.1 elements would instead be
truncated.
An integer truncation in OpenSSL's ASN.1 decoder causes the content length of
an ASN.1 primitive element to be mishandled when it exceeds 2 gigabytes. In the
worst case the truncated length is treated as a request to scan the binary
content for a terminating zero byte, possibly causing OpenSSL to read either
less than or beyond the end of the allocated buffer.
Applications that pass attacker-supplied data to d2i_X509(), d2i_PKCS7(), or
any other d2i_* decoding function are affected. OpenSSL's own command-line
tools are not vulnerable, as data read through the BIO layer is checked before
it reaches the affected code. The issue only affects 64-bit Unix and Unix-like
platforms; 32-bit platforms and 64-bit Windows are not 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.
CVSS Score
7.5
EPSS Score
0.01
Published
2026-06-09
Issue Summary: The PKCS#12 file processing fails to perform sufficient input
validation for files that use Password-Based Message Authentication Code 1
(PBMAC1) integrity mechanism allowing a certificate and private key forgery.
Impact Summary: An attacker impersonating a user can cause a service reading
PKCS#12 files to accept forged certificates and private keys with a 1 in 256
probability.
If a service accepting PKCS#12 files is using passwords for authenticating
the received files, the attacker can create unencrypted PKCS#12 files that
use PBMAC1 authentication that specifies an HMAC key of only one byte, allowing
them to craft a file that will be accepted with a 1 in 256 probability.
That would then cause the service to accept a certificate and private key
controlled by the attacker.
The FIPS modules are not affected by this issue, as the affected code is
outside the OpenSSL FIPS module boundary.
CVSS Score
7.4
EPSS Score
0.002
Published
2026-06-09