ESB-2026.3960 — Vulnetix

ESB-2026.3960 PUBLISHED CVSS 7.5 HIGH

=========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2026.3960 gvisor-tap-vsock security update 21 April 2026 =========================================================================== AUSCERT Security Bulletin Summary --------------------------------- Product: gvisor-tap-vsock Publisher: Red Hat Operating System: Red Hat Resolution: Patch/Upgrade CVE Names: CVE-2025-68121 CVE-2026-25679 CVE-2025-61726 CVE-2025-61729 Original Bulletin: https://access.redhat.com/errata/RHSA-2026:9108 Comment: CVSS (Max): 7.5 CVE-2026-25679 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) CVSS Source: Red Hat Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H EPSS (Max): 0.0% (9th) CVE-2025-61726 2026-04-20 - --------------------------BEGIN INCLUDED TEXT-------------------- RHSA-2026:9108 - Security Advisory Issued: 2026-04-20 Updated: 2026-04-20 Synopsis Gvisor-tap-vsock security update Type/Severity Security Advisory: Important Topic An update for gvisor-tap-vsock is now available for Red Hat Enterprise Linux 9.6 Extended Update Support. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section. Description A replacement for libslirp and VPNKit, written in pure Go. It is based on the network stack of gVisor. Compared to libslirp, gvisor-tap-vsock brings a configurable DNS server and dynamic port forwarding. Security Fix(es): o crypto/x509: golang: Denial of Service due to excessive resource consumption via crafted certificate (CVE-2025-61729) o golang: net/url: Memory exhaustion in query parameter parsing in net/url (CVE-2025-61726) o crypto/tls: Unexpected session resumption in crypto/tls (CVE-2025-68121) o net/url: Incorrect parsing of IPv6 host literals in net/url (CVE-2026-25679) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Solution For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Affected Products o Red Hat Enterprise Linux for x86_64 - Extended Update Support 9.6 x86_64 o Red Hat Enterprise Linux Server - AUS 9.6 x86_64 o Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.6 s390x o Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.6 ppc64le o Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.6 aarch64 o Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.6 ppc64le o Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.6 x86_64 o Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.6 aarch64 o Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.6 s390x o Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.6 x86_64 o Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.6 aarch64 o Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.6 ppc64le o Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.6 s390x Fixes o BZ - 2418462 - CVE-2025-61729 crypto/x509: golang: Denial of Service due to excessive resource consumption via crafted certificate o BZ - 2434432 - CVE-2025-61726 golang: net/url: Memory exhaustion in query parameter parsing in net/url o BZ - 2437111 - CVE-2025-68121 crypto/tls: crypto/tls: Incorrect certificate validation during TLS session resumption o BZ - 2445356 - CVE-2026-25679 net/url: Incorrect parsing of IPv6 host literals in net/url CVEs o CVE-2025-61726 o CVE-2025-61729 o CVE-2025-68121 o CVE-2026-25679 References o https://access.redhat.com/security/updates/classification/#important - --------------------------END INCLUDED TEXT---------------------- You have received this e-mail bulletin as a result of your organisation's registration with AUSCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AUSCERT's members. As AUSCERT did not write the document quoted above, AUSCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AUSCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://portal.auscert.org.au/bulletins/ =========================================================================== AUSCERT The University of Queensland, Brisbane QLD 4072 Australia e: auscert@auscert.org.au t: +61 (0)7 3365 4417 Allies in Cyber Security ===========================================================================

Risk Scores

CVSS v3.1

7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Products

Vendor	Product	Versions
Red Hat	gvisor-tap-vsock

Timeline

Apr 20, 2026 CVE Published
Apr 21, 2026 Distribution Patch

References

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