Security readout for executives and security teams
Plain-English summary
CVE-2026-1425 is a remotely reachable stack buffer overflow in pymumu SmartDNS versions up to 47.1, involving SVCB/HTTPS DNS record parsing. Public sources rate it medium severity because exploitation is high complexity and considered difficult. No provided source or KEV status indicates active exploitation.
Executive priority
Address in normal vulnerability remediation cycles, escalating for internet-exposed SmartDNS deployments. The issue is remote and memory-corruption based, but current public evidence points to medium severity, high exploitation complexity, and no confirmed active exploitation.
Technical view
The flaw affects src/dns.c functions _dns_decode_rr_head and _dns_decode_SVCB_HTTPS in the SVCB/HTTPS record parser. Crafted input can cause a stack-based buffer overflow. CVSS v4.0 is 6.3 with network attack vector, no privileges or user interaction, high attack complexity, and limited confidentiality, integrity, and availability impact.
Likely exposure
Organizations running pymumu SmartDNS 47.0, 47.1, or earlier affected builds may be exposed, especially where SmartDNS processes untrusted DNS traffic. Exposure depends on deployed version, network reachability, and whether the patch commit is present.
Exploitation context
The vulnerability is remotely triggerable, but public scoring indicates high complexity and difficult exploitability. The source bundle does not show KEV listing, public exploitation in the wild, or a weaponized exploit. Treat internet-reachable resolvers as higher priority for review.
Researcher notes
Public details identify CWE-119 and CWE-121 in SVCB/HTTPS DNS record decoding. Evidence names the vulnerable functions and patch commit, but does not provide a versioned fixed release in the supplied sources. Avoid assuming exploitability beyond the stated difficult, high-complexity assessment.
Mitigation direction
- Apply the vendor patch identified as commit 2d57c4b4e1add9b4537aeb403f794a084727e1c8.
- Upgrade SmartDNS when a vendor release containing the patch is available.
- Restrict SmartDNS exposure to trusted networks where operationally possible.
- Monitor vendor repository and advisories for versioned release guidance.
Validation and detection
- Inventory SmartDNS deployments and record exact versions.
- Check whether affected instances include commit 2d57c4b4e1add9b4537aeb403f794a084727e1c8.
- Prioritize externally reachable SmartDNS services for remediation.
- Review service stability logs for unexplained crashes, without attempting exploit reproduction.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-119: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-121: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-1425 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.3 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
6.3MediumVector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X
Source materials
- CVE List V5 sourceCVE List V5
- VDB-342841 | pymumu SmartDNS SVBC Record dns.c _dns_decode_SVCB_HTTPS stack-based overflowCVE reference · vdb-entry, technical-description
- VDB-342841 | CTI Indicators (IOB, IOC, IOA)CVE reference · signature, permissions-required
- Submit #736827 | pymumu smartdns 47.1 Stack-based Buffer OverflowCVE reference · third-party-advisory
- https://github.com/pymumu/smartdns/commit/2d57c4b4e1add9b4537aeb403f794a084727e1c8CVE reference · patch
- https://github.com/pymumu/smartdns/CVE reference · product
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Stack-based Buffer Overflow
Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.