CVE-2025-8129 | KoaJS Koa HTTP Header response.js back redirect

Exp

A vulnerability, which was classified as problematic, was found in KoaJS Koa up to 3.0.0. Affected is the function back in the library lib/response.js of the component HTTP Header Handler. The manipulation of the argument Referrer leads to open redirect. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.

Published: 2025-07-25 Last update: 2026-04-29 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-8129 is rated Exploit Available (50/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.26%). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2025-8129

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2025-8129

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 2026-05-21 0.05% 0.26% +0.21%
2 2026-01-02 0.04% 0.05% +0.01%
3 2025-12-21 — 0.04% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-8129

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
2.0 4.0 LOW
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:L)
Low privileges are required.
User interaction (UI:P)
A user has to participate (for example click/open/approve).
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:L)
Limited integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:P)
Proof-of-concept: public PoC exists; no reported exploitation and no known simplification tools.
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.
 — — [email protected]
3.5 3.1 LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/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:L)
A normal user session is enough; they don’t have to be admin.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.1 1.4 [email protected]
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/C:N/I:P/A:N 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:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.0 2.9 [email protected]

Weakness enumeration for CVE-2025-8129

GitHub Security Advisory for CVE-2025-8129

GHSA-jgmv-j7ww-jx2x · Severity: low · Ecosystem: npm — Koa Open Redirect via Referrer Header (User-Controlled)

OS Trackers for CVE-2025-8129

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2025-8129
suse low CVE-2025-8129 severity low: SUSE including 34 source package names (corepack20, corepack22, …), 173 product×package rows across 22 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS, … (22 product lines)): Known Not Affected 173. https://www.suse.com/security/cve/CVE-2025-8129/

Affected software / configurations for CVE-2025-8129

Vendor Product Version Raw CPE
koajs koa >= 2.0.0, < 2.16.2 cpe:2.3:a:koajs:koa:*:*:*:*:*:node.js:*:*
koajs koa 3.0.0 cpe:2.3:a:koajs:koa:3.0.0:-:*:*:*:node.js:*:*
koajs koa 3.0.0 cpe:2.3:a:koajs:koa:3.0.0:alpha0:*:*:*:node.js:*:*
koajs koa 3.0.0 cpe:2.3:a:koajs:koa:3.0.0:alpha1:*:*:*:node.js:*:*
koajs koa 3.0.0 cpe:2.3:a:koajs:koa:3.0.0:alpha2:*:*:*:node.js:*:*
koajs koa 3.0.0 cpe:2.3:a:koajs:koa:3.0.0:alpha3:*:*:*:node.js:*:*
koajs koa 3.0.0 cpe:2.3:a:koajs:koa:3.0.0:alpha4:*:*:*:node.js:*:*
koajs koa 3.0.0 cpe:2.3:a:koajs:koa:3.0.0:alpha5:*:*:*:node.js:*:*

References for CVE-2025-8129

URL Tags
https://github.com/koajs/koa/issues/1892 Exploit Issue Tracking Patch Vendor Advisory
https://github.com/koajs/koa/issues/1892#issue-3213028583 Exploit Issue Tracking Patch Third Party Advisory Vendor Advisory
https://vuldb.com/?ctiid.317514 Permissions Required VDB Entry
https://vuldb.com/?id.317514 Third Party Advisory VDB Entry
https://vuldb.com/?submit.619741 Third Party Advisory VDB Entry
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