Debian LTS recently issued an advisory for the nghttp2 library to patch CVE-2026-27135, which resolves a missing state validation that previously triggered assertion failures. A separate update addresses CVE-2026-30922 in pyasn1, fixing a denial of service flaw caused by uncontrolled recursion when processing deeply nested ASN.1 data. Both issues threaten system stability and require administrators to upgrade their packages immediately. You can find complete installation guidance and ongoing threat details on the official Debian security trackers.

[DLA 4581-1] nghttp2 security update
ELA-1717-1 pyasn1 security update

[SECURITY] [DLA 4581-1] nghttp2 security update

-------------------------------------------------------------------------
Debian LTS Advisory DLA-4581-1 debian-lts@lists.debian.org
https://www.debian.org/lts/security/ Lukas Märdian
May 13, 2026 https://wiki.debian.org/LTS
-------------------------------------------------------------------------

Package : nghttp2
Version : 1.43.0-1+deb11u3
CVE ID : CVE-2026-27135
Debian Bug : 1131369

A vulnerabilitie was discovered in nghttp2, a server, proxy and client
implementing HTTP/2.

CVE-2026-27135

Fix missing iframe->state validations to avoid assertion failure. As
backported from upstream v1.68.1 (commit 5c7df8f), incl. upstream test case
from commit c619c7be0737ac78051b1cacf4b1ce5467eb838d.

For Debian 11 bullseye, this problem has been fixed in version
1.43.0-1+deb11u3.

We recommend that you upgrade your nghttp2 packages.

For the detailed security status of nghttp2 please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/nghttp2

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://wiki.debian.org/LTS

ELA-1717-1 pyasn1 security update (by )

Package : pyasn1


Version : 0.1.9-2+deb9u2 (stretch), 0.4.2-3+deb10u2 (buster)


Related CVEs :

CVE-2026-30922



pyasn1 is vulnerable to a Denial of Service (DoS) attack caused by uncontrolled
recursion when decoding ASN.1 data with deeply nested structures. This vulnerability
can force the decoder to recursively call itself until the Python interpreter
crashes with a RecursionError or consumes all available memory, crashing the host
application.

ELA-1717-1 pyasn1 security update (by )