CVE-2026-3591 | ISC BIND prior 9.20.21/9.21.20 named return of stack variable address

VDB-353136 · CVE-2026-3591 · GCVE-0-2026-3591 ISC BIND PRIOR 9.20.21/9.21.20 NAMED RETURN OF STACK VARIABLE ADDRESS HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 5.7 $0-$5k 1.49+ Summaryinfo A vulnerability classified as critical was found in ISC BIND up to 9.18.45/9.18.46-S0/9.20.20/9.20.20-S1/9.21.19. This vulnerability affects unknown code of the component named. The manipulation results in return of stack variable address. This vulnerability is identified as CVE-2026-3591. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is advised. Detailsinfo A vulnerability, which was classified as critical, was found in ISC BIND up to 9.18.45/9.18.46-S0/9.20.20/9.20.20-S1/9.21.19. Affected is an unknown function of the component named. The manipulation with an unknown input leads to a return of stack variable address vulnerability. CWE is classifying the issue as CWE-562. A function returns the address of a stack variable, which will cause unintended program behavior, typically in the form of a crash. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes: A use-after-return vulnerability exists in the `named` server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected. The advisory is shared for download at kb.isc.org. This vulnerability is traded as CVE-2026-3591 since 03/05/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 03/25/2026). Upgrading to version 9.20.21 or 9.21.20 eliminates this vulnerability. Productinfo Type Domain Name Software Vendor ISC Name BIND Version 9.18.0 9.18.1 9.18.2 9.18.3 9.18.4 9.18.5 9.18.6 9.18.7 9.18.8 9.18.9 9.18.10 9.18.11 9.18.12 9.18.13 9.18.14 9.18.15 9.18.16 9.18.17 9.18.18 9.18.19 9.18.20 9.18.21 9.18.22 9.18.23 9.18.24 9.18.25 9.18.26 9.18.27 9.18.28 9.18.29 9.18.30 9.18.31 9.18.32 9.18.33 9.18.34 9.18.35 9.18.36 9.18.37 9.18.38 9.18.39 9.18.40 9.18.41 9.18.42 9.18.43 9.18.44 9.18.45 9.18.46-S0 9.20.0 9.20.1 9.20.2 9.20.3 9.20.4 9.20.5 9.20.6 9.20.7 9.20.8 9.20.9 9.20.10 9.20.11 9.20.12 9.20.13 9.20.14 9.20.15 9.20.16 9.20.17 9.20.18 9.20.19 9.20.20 9.20.20-S1 9.21.0 9.21.1 9.21.2 9.21.3 9.21.4 9.21.5 9.21.6 9.21.7 9.21.8 9.21.9 9.21.10 9.21.11 9.21.12 9.21.13 9.21.14 9.21.15 9.21.16 9.21.17 9.21.18 9.21.19 License open-source Website Vendor: https://www.isc.org/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 5.9 VulDB Meta Temp Score: 5.7 VulDB Base Score: 6.3 VulDB Temp Score: 6.0 VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA Base Score: 5.4 CNA Vector (isc): 🔒 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Return of stack variable address CWE: CWE-562 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: BIND 9.20.21/9.21.20 Timelineinfo 03/05/2026 CVE reserved 03/25/2026 +20 days Advisory disclosed 03/25/2026 +0 days VulDB entry created 03/25/2026 +0 days VulDB entry last update Sourcesinfo Vendor: isc.org Advisory: kb.isc.org Status: Confirmed CVE: CVE-2026-3591 (🔒) GCVE (CVE): GCVE-0-2026-3591 GCVE (VulDB): GCVE-100-353136 Entryinfo Created: 03/25/2026 15:21 Changes: 03/25/2026 15:21 (64) Complete: 🔍 Cache ID: 99:8F5:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸