CVE-2006-3251

Heap-based buffer overflow in the array_push function in hashcash.c for Hashcash before 1.21 might allow attackers to execute arbitrary code via crafted entries.

Published: 2006-06-27 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2006-3251 is rated Moderate Risk (62.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.59%). EPSS rose +1.65% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2006-3251

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 1.94% 3.59% +1.65%
2 2025-03-30 2.26% 1.94% -0.32%
3 2025-03-29 — 2.26% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2006-3251

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2006-3251

OS Trackers for CVE-2006-3251

vendor priority summary link
debian not yet assigned CVE-2006-3251 not yet assigned priority: Debian including 1 source packages (hashcash), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2006-3251
gentoo high CVE-2006-3251: 1 GLSA(s) (200606-25), 1 atom(s) (net-misc/hashcash); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2006-3251
ubuntu medium CVE-2006-3251 medium priority: Ubuntu including 1 source packages (hashcash), 5 status rows across 5 suites (dapper, edgy, feisty, gutsy, upstream): released 5. https://ubuntu.com/security/CVE-2006-3251

Affected software / configurations for CVE-2006-3251

Vendor Product Version Raw CPE
hashcash hashcash <= 1.20 cpe:2.3:a:hashcash:hashcash:*:*:*:*:*:*:*:*
hashcash hashcash 1.00 cpe:2.3:a:hashcash:hashcash:1.00:*:*:*:*:*:*:*
hashcash hashcash 1.01 cpe:2.3:a:hashcash:hashcash:1.01:*:*:*:*:*:*:*
hashcash hashcash 1.02 cpe:2.3:a:hashcash:hashcash:1.02:*:*:*:*:*:*:*
hashcash hashcash 1.03 cpe:2.3:a:hashcash:hashcash:1.03:*:*:*:*:*:*:*
hashcash hashcash 1.04 cpe:2.3:a:hashcash:hashcash:1.04:*:*:*:*:*:*:*
hashcash hashcash 1.05 cpe:2.3:a:hashcash:hashcash:1.05:*:*:*:*:*:*:*
hashcash hashcash 1.06 cpe:2.3:a:hashcash:hashcash:1.06:*:*:*:*:*:*:*
hashcash hashcash 1.07 cpe:2.3:a:hashcash:hashcash:1.07:*:*:*:*:*:*:*
hashcash hashcash 1.08 cpe:2.3:a:hashcash:hashcash:1.08:*:*:*:*:*:*:*
hashcash hashcash 1.09 cpe:2.3:a:hashcash:hashcash:1.09:*:*:*:*:*:*:*
hashcash hashcash 1.10 cpe:2.3:a:hashcash:hashcash:1.10:*:*:*:*:*:*:*
hashcash hashcash 1.11 cpe:2.3:a:hashcash:hashcash:1.11:*:*:*:*:*:*:*
hashcash hashcash 1.12 cpe:2.3:a:hashcash:hashcash:1.12:*:*:*:*:*:*:*
hashcash hashcash 1.13 cpe:2.3:a:hashcash:hashcash:1.13:*:*:*:*:*:*:*
hashcash hashcash 1.14 cpe:2.3:a:hashcash:hashcash:1.14:*:*:*:*:*:*:*
hashcash hashcash 1.15 cpe:2.3:a:hashcash:hashcash:1.15:*:*:*:*:*:*:*
hashcash hashcash 1.16 cpe:2.3:a:hashcash:hashcash:1.16:*:*:*:*:*:*:*
hashcash hashcash 1.17 cpe:2.3:a:hashcash:hashcash:1.17:*:*:*:*:*:*:*
hashcash hashcash 1.18 cpe:2.3:a:hashcash:hashcash:1.18:*:*:*:*:*:*:*
hashcash hashcash 1.19 cpe:2.3:a:hashcash:hashcash:1.19:*:*:*:*:*:*:*

References for CVE-2006-3251

cvelogic Threat Intelligence