Security Affairs newsletter Round 553 by Pierluigi Paganini

CVE-2025-55182 is a critical (CVSS 10.0) pre-authentication remote code execution flaw (CWE-502, deserialization of untrusted data) in React Server Components, specifically the react-server-dom-parcel, react-server-dom-turbopack, and react-server-dom-webpack packages in versions 19.0.0, 19.1.0, 19.1.1, and 19.2.0. It is triggered when the vulnerable code unsafely deserializes payloads from HTTP requests sent to Server Function endpoints, requiring no authentication or user interaction. An attacker gains arbitrary code execution on the affected server (CVSS scope changed, with high impact to confidentiality, integrity, and availability), and reporting notes a campaign in which hackers used the flaw to breach 766 Next.js hosts and steal credentials. Any React/Next.js application exposing Server Functions with the affected React versions is in scope, which given the ubiquity of React and Next.js is a very large deployed base. Exploitation is confirmed in the wild: the flaw was added to CISA's Known Exploited Vulnerabilities catalog on 2025-12-05 with known ransomware use, EPSS puts the 30-day exploitation probability at 99.8%, multiple public PoC/scanner repositories are available, and coverage has dubbed the flaw React2Shell.

Do: Upgrade the react-server-dom-webpack, react-server-dom-parcel, and react-server-dom-turbopack packages to the vendor-patched releases (any version later than the vulnerable 19.0.0, 19.1.0, 19.1.1, and 19.2.0 line) and update Next.js per Vercel's advisory; as a KEV entry, U.S. federal agencies must apply vendor mitigations per BOD 22-01 or discontinue use. Audit internet-exposed Server Function endpoints for the vulnerable React versions and review logs for exploitation activity, including the reported campaign that breached 766 Next.js hosts and stole credentials, then rotate any exposed credentials.

Apache Tika is vulnerable to XML External Entity (XXE) injection (CWE-611), rated critical at CVSS 9.8 (network-exploitable, no privileges or user interaction required), with the vulnerable code residing in tika-core but reachable through the PDF parser when it processes the XFA form embedded in a PDF. An attacker who can get Tika to parse a crafted PDF, typically by submitting a document to a Tika-based service or tika-server endpoint, can have the XML parser resolve external entities, gaining arbitrary local file read and SSRF from the Tika process, with CVSS impact rated high for confidentiality, integrity and availability. All platforms are affected across tika-core 1.13–3.2.1, tika-parser-pdf-module 2.0.0–3.2.1, and the 1.x tika-parsers module 1.13–1.28.5; notably the fix is in tika-core (3.2.2+), so upgrading only the PDF module leaves deployments vulnerable, and 1.x users need fixes in the tika-parsers module. Anyone running affected Tika versions to process untrusted PDFs is exposed, including standalone tika-server instances and downstream applications that embed Tika (vendors such as Atlassian have shipped fixes for embedded Tika). There is no CISA KEV listing and no public PoC or confirmed in-the-wild exploitation known, but EPSS puts it in the 100th percentile with an 80.3% probability of exploitation within 30 days.

Do: Upgrade tika-core to 3.2.2 or later (upgrading only tika-parser-pdf-module is insufficient), and keep tika-parser-pdf-module aligned on the fixed 3.x line; users on the 1.x line should upgrade both tika-parsers and tika-core to the patched 1.x releases. If you consume Tika through another product (e.g., Solr-based stacks or Atlassian products), apply that vendor's patch. Until patched, avoid parsing untrusted PDFs with affected Tika versions, and restrict the Tika process's file-system and network access to limit file-read and SSRF impact.