AlmaLinux 9.6 [TuxCare] Security Update: python3-unbound / unbound / unbound-devel / unbound-dracut / etc Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1785490706)

high Nessus Plugin ID 359992

Synopsis

The AlmaLinux host is missing one or more security updates.

Description

The AlmaLinux 9.6 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare ALMALINUX9.6:CLSA-2026:1785490706 advisory.

- DISPUTE NOTE: this issue does not pose a security risk as it (according to analysis by the original software developer, NLnet Labs) falls within the expected functionality and security controls of the application. Red Hat has made a claim that there is a security risk within Red Hat products. NLnet Labs has no further information about the claim, and suggests that affected Red Hat customers refer to available Red Hat documentation or support channels. ORIGINAL DESCRIPTION: A NULL pointer dereference flaw was found in the ub_ctx_set_fwd function in Unbound. This issue could allow an attacker who can invoke specific sequences of API calls to cause a segmentation fault. When certain API functions such as ub_ctx_set_fwd and ub_ctx_resolvconf are called in a particular order, the program attempts to read from a NULL pointer, leading to a crash. This issue can result in a denial of service by causing the application to terminate unexpectedly. (CVE-2024-43167)

- In NLnet Labs Unbound 1.7.0 up to and including 1.25.1, insufficient validation of the RRSIG.Labels field combined with premature cache writes during RFC 8198 aggressive NSEC processing leads to cache poisoning that permits a malicious actor controlling a single delegated zone to poison arbitrary sibling zones under NSEC-signed parent domains. A malicious actor with one registered domain under an NSEC-signed TLD can serve malicious insecure DNS responses for unrelated sibling domains (sharing the same parent zone).
Arbitrary delegations that do not exist under the parent domain and are covered by the parent's NSEC chain can be brought into insecure existence by fraudulent wildcard DS records (less labels than expected, unknown algorithm) from the malicious sibling domain. This allows the malicious actor to inject insecure wildcard records for those delegations. (CVE-2026-44690)

- In NLnet Labs Unbound up to and including version 1.25.1, when the validator builds the canonical RDATA form for an RRSIG-covered PX/RP/MINFO/SOA RRset, it computes the address of the second embedded domain name as 'datstart + dname_valid(datstart, ...)' and passes it straight to 'query_dname_tolower()' without checking that a second name is actually present in the RDATA. The wire-format parser accepts multi-dname RRs whose RDATA ends after the first name, so an attacker who runs a DNSSEC-signed authoritative server can deliver a record with an absent second domain name (e.g. SOA record) and cause 'query_dname_tolower()' to walk label-by-label through stale bytes in the per-worker 'env->scratch_buffer', past the end of that heap allocation if 'msg-buffer-size' has been lowered from the default. This leads to heap buffer overflow and on a release build the outcome relies heavily on the contents of the buffer tail and the adjacent heap chunk. (CVE-2026-56416)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages based on the guidance in TuxCare advisory ALMALINUX9.6:CLSA-2026:1785490706.

Plugin Details

Severity: High

ID: 359992

File Name: tuxcare_alma_linux_9.6_CLSA-2026-1785490706.nasl

Version: 1.1

Type: Local

Family: Alma Linux Local Security Checks

Published: 10/1/2026

Updated: 10/1/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.63

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:N

CVSS Score Source: CVE-2026-44690

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/AlmaLinux/release, Host/AlmaLinux/rpm-list, Host/OS/extended-third-party

Exploit Ease: No known exploits are available

Patch Publication Date: 7/31/2026

Vulnerability Publication Date: 8/8/2024

Reference Information

CVE: CVE-2024-43167, CVE-2026-44690, CVE-2026-56416

CLSA: 2026:1785490706

Detections

Analytics