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.
3 results
May 15, 2026LibJWT is a C JSON Web Token Library.CVE-2026-44699 · Other software · benmcollins · reported by GitHubCritical 9.1
LibJWT is a C JSON Web Token Library. From 3.0.0 to 3.3.2, libjwt accepts an RSA JWK that does not contain an alg parameter as the verification key for an HS256/HS384/HS512 token. In the OpenSSL backend, this causes HMAC verification to run with a zero-length key, so an attacker can forge a valid JWT without knowing any secret or RSA private key. This is an algorithm-confusion authentication bypass. It affects applications that load RSA keys from JWKS where alg is omitted, which is valid JWK syntax and common in real deployments, and then choose the verification algorithm from the JWT header, for example in a kid lookup callback. This vulnerability is fixed in 3.3.3.
- Product
- libjwt
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Mar 27, 2026LibJWT is a C JSON Web Token Library.CVE-2026-33996 · Other software · benmcollins · reported by GitHubMedium 5.8
LibJWT is a C JSON Web Token Library. Starting in version 3.0.0 and prior to version 3.3.0, the JWK parsing for RSA-PSS did not protect against a NULL value when expecting to parse JSON string values. A specially crafted JWK file could exploit this behavior by using integers in places where the code expected a string. This was fixed in v3.3.0. A workaround is available. Users importing keys through a JWK file should not do so from untrusted sources. Use the `jwk2key` tool to check for validity of a JWK file. Likewise, if possible, do not use JWK files with RSA-PSS keys.
- Product
- libjwt
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Feb 8, 2024libjwt 1.15.3 uses strcmp (which is not constant time) to verify authentication, which makes it easier to bypass authentication via a timing side channel.CVE-2024-25189 · Other software · bencollins · reported by MITRECritical 9.8
libjwt 1.15.3 uses strcmp (which is not constant time) to verify authentication, which makes it easier to bypass authentication via a timing side channel.
- Product
- jwt_c_library
- What to do
- Apply the vendor’s update. The NVD record links to the advisory.
Full record and what to do →NVD recordgithub.comlists.debian.org
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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