sniproxy NULL pointer dereference in resolv_cancel() allows remote daemon crash
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-476.
Summary
sniproxy through 0.7.0 contains a NULL pointer dereference in resolv_cancel() (CWE-476). A remote, unauthenticated attacker can crash the daemon by sending a 254 or 255 character TLS SNI name or HTTP Host header that matches a wildcard backend, then closing the connection. The CVSS 4.0 base score is 8.7 (HIGH).
Written with Claude Haiku 5.5 from the sources below · 2026-10-31
Description from the CNA
sniproxy through 0.7.0 contains a NULL pointer dereference vulnerability in resolv_cancel() that allows remote unauthenticated attackers to crash the daemon by sending overlong hostnames. Attackers can send a 254 or 255 character TLS SNI name or HTTP Host header matching a wildcard backend, then close the connection to terminate the proxy.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| dlundquist | sniproxy | up to 0.7.0 | — | No fix listed | CNA |
- sniproxy Vendordlundquist Affected up to 0.7.0 Fixed in — No fix listed CNA
Remediation
No fixed version is listed for sniproxy through 0.7.0, so this record names no upgrade target. Watch the upstream sniproxy project for a patched release.
Written with Claude Haiku 5.5 from the sources below · 2026-10-31
Timeline
- 2026-10-30 Threatist record created from CVE-2026-119760
- 2026-10-30 Alias added: GHSA-v5q9-7x5c-3phf
- 2026-11-01 Priority changed: MEDIUM → LOW
- 2026-11-05 CISA SSVC decision points changed
- 2026-11-05 Priority changed: LOW → MEDIUM
References
Patch 2
Other 4
- https://github.com/dlundquist/sniproxy/issues/411
- https://github.com/dlundquist/sniproxy/blob/1cc625ea41796695a54593d1bd779366b82b8b4e/src/connection.c#L737-L738
- https://github.com/dlundquist/sniproxy/blob/1cc625ea41796695a54593d1bd779366b82b8b4e/src/resolv.c#L219-L224
- https://github.com/dlundquist/sniproxy
Sources
- CVE-2026-119760 · CVE Program
- CVE-2026-119760 · NVD
- FIRST EPSS
- GHSA-v5q9-7x5c-3phf · GitHub Advisory Database · CC BY 4.0
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