Several Debian LTS advisories were released covering vulnerabilities in the web application firewall ModSecurity, the ASN.1 library pyasn1, and the asynchronous web framework Tornado. The modsecurity‑apache update addresses CVE-2025-54571 by preventing attackers from overriding HTTP response Content-Type headers, while the pyasn1 updates fix a denial‑of‑service flaw that can exhaust memory when parsing malformed OID/RELATIVE-OID values (CVE-2026-23490). The python-tornado advisories cover three CVEs, CVE-2025-67724, CVE-2025-67725, and CVE-2025-67726, which expose issues such as XSS, header injection, and quadratic performance attacks that can lead to denial of service. All affected packages have been upgraded to patched versions, and users are urged to install the latest releases promptly.
Debian GNU/Linux 9 (Stretch) Extended LTS:
ELA-1633-1 modsecurity-apache security update
Debian GNU/Linux 9 (Stretch) and 10 (Buster) Extended LTS:
ELA-1634-1 pyasn1 security update
Debian GNU/Linux 10 (Buster) Extended LTS:
ELA-1635-1 python-tornado security update
Debian GNU/Linux 11 (Bullseye) LTS:
[DLA 4463-1] pyasn1 security update