CVE-2026-28681 | IRRd: web UI host header injection allows password reset poisoning via attacker-controlled email links

Internet Routing Registry daemon version 4 is an IRR database server, processing IRR objects in the RPSL format. From version 4.4.0 to before version 4.4.5 and from version 4.5.0 to before version 4.5.1, an attacker can manipulate the HTTP Host header on a password reset or account creation request. The confirmation link in the resulting email can then point to an attacker-controlled domain. Opening the link in the email is sufficient to pass the token to the attacker, who can then use it on the real IRRD instance to take over the account. A compromised account can then be used to modify RPSL objects maintained by the account's mntners and perform other account actions. If the user had two-factor authentication configured, which is required for users with override access, an attacker is not able to log in, even after successfully resetting the password. This issue has been patched in versions 4.4.5 and 4.5.1.

Published: 2026-03-06 Last update: 2026-04-21 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-28681 is rated Low Risk (35.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.03%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2026-28681

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 2026-04-21 0.06% 0.03% -0.03%
2 2026-03-06 — 0.06% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-28681

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 5.2 [email protected]

Weakness enumeration for CVE-2026-28681

GitHub Security Advisory for CVE-2026-28681

GHSA-22m3-c7vp-49fj · Severity: high · Ecosystem: pip — IRRd: web UI host header injection allows password reset poisoning via attacker-controlled email links

Affected software / configurations for CVE-2026-28681

Vendor Product Version Raw CPE
internet_routing_registry_daemon_project internet_routing_registry_daemon >= 4.4.0, < 4.4.5 cpe:2.3:a:internet_routing_registry_daemon_project:internet_routing_registry_daemon:*:*:*:*:*:*:*:*
internet_routing_registry_daemon_project internet_routing_registry_daemon >= 4.5.0, < 4.5.1 cpe:2.3:a:internet_routing_registry_daemon_project:internet_routing_registry_daemon:*:*:*:*:*:*:*:*

References for CVE-2026-28681

cvelogic Threat Intelligence