CVE-2025-5994

highpriority · track · 0EPSS 0.002 · 12 %ileDEEURU
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.22% (12th) EPSS
CVSS 7.5 · high
Is it mine?
14 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

A multi-vendor cache poisoning vulnerability named 'Rebirthday Attack' has been discovered in caching resolvers that support EDNS Client Subnet (ECS). Unbound is also vulnerable when compiled with ECS support, i.e., '--enable-subnet', AND configured to send ECS information along with queries to upstream name servers, i.e., at least one of the 'send-client-subnet', 'client-subnet-zone' or 'client-subnet-always-forward' options is used. Resolvers supporting ECS need to segregate outgoing queries to accommodate for different outgoing ECS information. This re-opens up resolvers to a birthday paradox attack (Rebirthday Attack) that tries to match the DNS transaction ID in order to cache non-ECS poisonous replies.

01

cvss

Technical severity, 0–10. One row per scoring source.

8.7
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–8.7

v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nsecondary · FSTEC (BDU) RU
v4.08.7highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/R:U/V:Csecondary · ENISA EU
v4.08.7highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/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:U/V:C/RE:X/U:Xsecondary · sep@nlnetlabs.nl
v4.06.6mediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/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:U/V:C/RE:X/U:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-349USCWE-349US
04

affected products (14)

Products and version ranges known to be affected.

05

advisories (3)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2025-1656Red Hat Enterprise Linux (unbound): Schwachstelle ermöglicht Manipulation von DatenDeutsch2025-07-27csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Red Hat Enterprise Linux (unbound) ausnutzen, um Daten zu manipulieren.

  • WID-SEC-W-2025-2043IBM QRadar SIEM: Mehrere SchwachstellenDeutsch2025-09-11csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in IBM QRadar SIEM ausnutzen, um beliebigen Programmcode auszuführen, einen Denial of Service Zustand zu erzeugen, um Dateien zu manipulieren und um nicht nächer spezifizierte Auswirkungen zu erzielen..

  • WID-SEC-W-2026-0489Xerox FreeFlow Print Server: Mehrere Schwachstellen ermöglichen nicht spezifizierten AngriffDeutsch2026-02-23csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Xerox FreeFlow Print Server ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundNVDCVE.orgMITRE
published 2025-07-16modified 2026-09-01
08

references (7)

External citations — patches, advisories, analysis.

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