Vulnerability database
Every flaw the U.S. government’s cybersecurity agency (CISA) has confirmed attackers are using, plus the new WordPress plugin and theme bugs published each day, sorted by what they mean for a small business. We refresh it twice a day. If you see something your website or office runs, tell us.
17 results
Oct 9, 2026Privasys Go is a maintained fork of the Go programming language that adds RA-TLS support to crypto/tls.CVE-2026-108267 · Other software · Privasys · reported by GitHubCritical 9.1
Privasys Go is a maintained fork of the Go programming language that adds RA-TLS support to crypto/tls. Prior to privasys-v0.5.1-go1.26.5, challenge-mode RA-TLS certificates bound quote ReportData to the certificate public key and client nonce but not to the active TLS session. An attacker who obtained an enclave TLS private key could relay a genuine quote onto another connection, causing a relying party to accept a handshake terminated by the attacker as an attested enclave connection. This issue is fixed in privasys-v0.5.1-go1.26.5.
- Product
- go
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 8, 2026Multiple ECH outer extension references are not permitted under RFC 9849; previously, a client could send a well-crafted packet that could trigger memory exhausCVE-2026-97031 · Other software · Go standard library · reported by security@golang.orgHigh 7.5
Multiple ECH outer extension references are not permitted under RFC 9849; previously, a client could send a well-crafted packet that could trigger memory exhaustion in the server process by specifying multiple references. We now reject these as malformed and curb the memory amplification vector as a result.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Aug 13, 2026Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not.CVE-2026-56862 · Other software · Go standard library · reported by security@golang.orgHigh 7.5
Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not. As a result, a malicious client can keep sending KeyUpdate messages to force the server to keep performing key derivation operations indefinitely.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jul 8, 2026Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrCVE-2026-42505 · Other software · Go standard library · reported by security@golang.orgMedium 5.3
Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Apr 7, 2026If one side of the TLS connection sends multiple key update messages post-handshake in a single record, the connection can deadlock, causing uncontrolled consumCVE-2026-32283 · Other software · Go standard library · reported by security@golang.orgHigh 7.5
If one side of the TLS connection sends multiple key update messages post-handshake in a single record, the connection can deadlock, causing uncontrolled consumption of resources. This can lead to a denial of service. This only affects TLS 1.3.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Feb 19, 2026uTLS is a fork of crypto/tls, created to customize ClientHello for fingerprinting resistance while still using it for the handshake.CVE-2026-27017 · Other software · refraction-networking · reported by GitHubLow 2.3
uTLS is a fork of crypto/tls, created to customize ClientHello for fingerprinting resistance while still using it for the handshake. Versions 1.6.0 through 1.8.0 contain a fingerprint mismatch with Chrome when using GREASE ECH, related to cipher suite selection. When Chrome selects the preferred cipher suite in the outer ClientHello and for ECH, it does so consistently based on hardware support—for example, if it prefers AES for the outer cipher suite, it also uses AES for ECH. However, the Chrome parrot in uTLS hardcodes AES preference for outer cipher suites but selects the ECH cipher suite randomly between AES and ChaCha20. This creates a 50% chance of selecting ChaCha20 for ECH while using AES for the outer cipher suite, a combination impossible in Chrome. This issue only affects GREASE ECH; in real ECH, Chrome selects the first valid cipher suite when AES is preferred, which uTLS handles correctly. This issue has been fixed in version 1.8.1.
- Product
- utls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Feb 19, 2026uTLS is a fork of crypto/tls, created to customize ClientHello for fingerprinting resistance while still using it for the handshake.CVE-2026-26994 · Other software · refraction-networking · reported by GitHubMedium 6.5
uTLS is a fork of crypto/tls, created to customize ClientHello for fingerprinting resistance while still using it for the handshake. In versions 1.6.7 and below, uTLS did not implement the TLS 1.3 downgrade protection mechanism specified in RFC 8446 Section 4.1.3 when using a uTLS ClientHello spec. This allowed an active network adversary to downgrade TLS 1.3 connections initiated by a uTLS client to a lower TLS version (e.g., TLS 1.2) by modifying the ClientHello message to exclude the SupportedVersions extension, causing the server to respond with a TLS 1.2 ServerHello (along with a downgrade canary in the ServerHello random field). Because uTLS did not check the downgrade canary in the ServerHello random field, clients would accept the downgraded connection without detecting the attack. This attack could also be used by an active network attacker to fingerprint uTLS connections. This issue has been fixed in version 1.7.0.
- Product
- utls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Feb 5, 2026During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between the initial handshake and the resumed handCVE-2025-68121 · Other software · Go standard library · reported by security@golang.orgCritical 10
During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between the initial handshake and the resumed handshake, the resumed handshake may succeed when it should have failed. This may happen when a user calls Config.Clone and mutates the returned Config, or uses Config.GetConfigForClient. This can cause a client to resume a session with a server that it would not have resumed with during the initial handshake, or cause a server to resume a session with a client that it would not have resumed with during the initial handshake.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jan 28, 2026During the TLS 1.3 handshake if multiple messages are sent in records that span encryption level boundaries (for instance the Client Hello and Encrypted ExtensiCVE-2025-61730 · Other software · Go standard library · reported by security@golang.orgMedium 5.3
During the TLS 1.3 handshake if multiple messages are sent in records that span encryption level boundaries (for instance the Client Hello and Encrypted Extensions messages), the subsequent messages may be processed before the encryption level changes. This can cause some minor information disclosure if a network-local attacker can inject messages during the handshake.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Oct 29, 2025When Conn.Handshake fails during ALPN negotiation the error contains attacker controlled information (the ALPN protocols sent by the client) which is not escapeCVE-2025-58189 · Other software · Go standard library · reported by security@golang.orgMedium 5.3
When Conn.Handshake fails during ALPN negotiation the error contains attacker controlled information (the ALPN protocols sent by the client) which is not escaped.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Dec 5, 2023Before Go 1.20, the RSA based TLS key exchanges used the math/big library, which is not constant time.CVE-2023-45287 · Other software · Go standard library · reported by security@golang.orgHigh 7.5
Before Go 1.20, the RSA based TLS key exchanges used the math/big library, which is not constant time. RSA blinding was applied to prevent timing attacks, but analysis shows this may not have been fully effective. In particular it appears as if the removal of PKCS#1 padding may leak timing information, which in turn could be used to recover session key bits. In Go 1.20, the crypto/tls library switched to a fully constant time RSA implementation, which we do not believe exhibits any timing side channels.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 8, 2023QUIC connections do not set an upper bound on the amount of data buffered when reading post-handshake messages, allowing a malicious QUIC connection to cause unCVE-2023-39322 · Other software · Go standard library · reported by security@golang.orgHigh 7.5
QUIC connections do not set an upper bound on the amount of data buffered when reading post-handshake messages, allowing a malicious QUIC connection to cause unbounded memory growth. With fix, connections now consistently reject messages larger than 65KiB in size.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Sep 8, 2023Processing an incomplete post-handshake message for a QUIC connection can cause a panic.CVE-2023-39321 · Other software · Go standard library · reported by security@golang.orgHigh 7.5
Processing an incomplete post-handshake message for a QUIC connection can cause a panic.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Aug 2, 2023Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures.CVE-2023-29409 · Other software · Go standard library · reported by security@golang.orgMedium 5.3
Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures. With fix, the size of RSA keys transmitted during handshakes is restricted to <= 8192 bits. Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Feb 28, 2023Large handshake records may cause panics in crypto/tls.CVE-2022-41724 · Other software · Go standard library · reported by security@golang.orgHigh 7.5
Large handshake records may cause panics in crypto/tls. Both clients and servers may send large TLS handshake records which cause servers and clients, respectively, to panic when attempting to construct responses. This affects all TLS 1.3 clients, TLS 1.2 clients which explicitly enable session resumption (by setting Config.ClientSessionCache to a non-nil value), and TLS 1.3 servers which request client certificates (by setting Config.ClientAuth >= RequestClientCert).
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Aug 10, 2022Non-random values for ticket_age_add in session tickets in crypto/tls before Go 1.17.11 and Go 1.18.3 allow an attacker that can observe TLS handshakes to correCVE-2022-30629 · Other software · Go standard library · reported by security@golang.orgLow 3.1
Non-random values for ticket_age_add in session tickets in crypto/tls before Go 1.17.11 and Go 1.18.3 allow an attacker that can observe TLS handshakes to correlate successive connections by comparing ticket ages during session resumption.
- Product
- crypto/tls
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Jul 15, 2021The crypto/tls package of Go through 1.16.5 does not properly assert that the type of public key in an X.509 certificate matches the expected type when doing a CVE-2021-34558 · Other software · Golang · reported by MITREMedium 6.5
The crypto/tls package of Go through 1.16.5 does not properly assert that the type of public key in an X.509 certificate matches the expected type when doing a RSA based key exchange, allowing a malicious TLS server to cause a TLS client to panic.
- Product
- GO
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgolang.orggroups.google.com
Where this comes from: the exploited list is CISA’s Known Exploited Vulnerabilities catalog. Everything else is the whole National Vulnerability Database, where each record is published by the team that found the bug (Wordfence, Patchstack, WPScan, the vendors themselves and others); we show who. Exploit odds are FIRST’s EPSS, updated daily. Titles and categories are ours, so check the linked record before acting on a detail. For a write-up of the big ones, see our advisories. Every vendor, and every WordPress plugin and theme with a recorded flaw, also has its own page. All of it is free to reuse as JSON, CSV or RSS.
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