Redis is an open source, in-memory database that persists on disk. In versions starting at 2.6 and prior to 7.4.3, An unauthenticated client can cause unlimited growth of output buffers, until the server runs out of memory or is killed. By default, the Redis configuration does not limit the output buffer of normal clients (see client-output-buffer-limit). Therefore, the output buffer can grow unlimitedly over time. As a result, the service is exhausted and the memory is unavailable. When password authentication is enabled on the Redis server, but no password is provided, the client can still cause the output buffer to grow from "NOAUTH" responses until the system will run out of memory. This issue has been patched in version 7.4.3. An additional workaround to mitigate this problem without patching the redis-server executable is to block access to prevent unauthenticated users from connecting to Redis. This can be done in different ways. Either using network access control tools like firewalls, iptables, security groups, etc, or enabling TLS and requiring users to authenticate using client side certificates.
CVE-2025-21605
“—” beside the score: it is equal to NVD's CVSS score.
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.9% (58th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2025-12407 (ENISA EUVD)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5HIGHmedium confidence
- EG Risk
- 49EG Risk 49/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity75% × 45%Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.9% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 0.9%
- EPSS %ILE
- 58th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- 0.9% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-26). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
April 23, 2025
Last Modified
February 10, 2026
Advisory Details (6)
Auto-updated Oct 19, 2026CVE-2025-21605 Mitigation Script - Memory Exhaustion Vulnerability in Redis Database - vsociety
https://www.vicarius.io/vsociety/posts/cve-2025-21605-mitigation-script-memory-exhaustion-vulnerability-in-redis-databaseCVE-2025-21605 Detection Script - Memory Exhaustion Vulnerability in Redis Database - vsociety
https://www.vicarius.io/vsociety/posts/cve-2025-21605-detection-script-memory-exhaustion-vulnerability-in-redis-database[SECURITY] [DLA 4162-1] redis security update
https://lists.debian.org/debian-lts-announce/2025/05/msg00014.html8.1.1
Patch available: valkey-io/valkey 8.1.1
https://github.com/valkey-io/valkey/releases/tag/8.1.1Redis DoS Vulnerability due to unlimited growth of output buffers abused by unauthenticated client · Advisory · redis/redis · GitHub
https://github.com/redis/redis/security/advisories/GHSA-r67f-p999-2gff7.4.3
Patch available: redis/redis 7.4.3
https://github.com/redis/redis/releases/tag/7.4.3Vendor Advisories for CVE-2025-21605(5)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHBA-2025:8213Red Hat Product SecurityHigh
Red Hat Bug Fix Advisory: Red Hat Quay v3.9.12 bug fix release
- RHBA-2025:8212Red Hat Product SecurityHigh
Red Hat Bug Fix Advisory: Red Hat Quay v3.10.11 bug fix release
- RHBA-2025:8687Red Hat Product SecurityHigh
Red Hat Bug Fix Advisory: Red Hat Quay v3.11.11 bug fix release
- RHBA-2025:8262Red Hat Product SecurityHigh
Red Hat Bug Fix Advisory: Red Hat Quay v3.14.2 bug fix release
- CVE-2025-21605Microsoft Security Response Center (MSRC)High
Redis DoS Vulnerability due to unlimited growth of output buffers abused by unauthenticated client
Patch Availability(15)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | quay/quay-rhel8:v3.12.10-3 | 2025-06-09 | redhat |
| redhat | quay/quay-rhel8:v3.14.2-7 | 2025-06-09 | redhat |
| redhat | quay/quay-rhel8:v3.11.11-5 | 2025-06-09 | redhat |
| redhat | discovery-installer-0:1.14.1-1.el9 | 2025-05-15 | redhat |
| redhat | redis:6-8100020250424123016.489197e6 | 2025-05-15 | redhat |
| redhat | redis:7-9040020250506191134.9 | 2025-05-14 | redhat |
| redhat | redis-0:6.2.18-1.el9_6 | 2025-05-13 | redhat |
| redhat | valkey-0:8.0.3-1.el10_0 | 2025-05-13 | redhat |
| redhat | redis:7-9060020250424140251.9 | 2025-05-13 | redhat |
| redhat | redis-0:6.2.7-1.el9_4.2 | 2025-05-12 | redhat |
| redhat | redis-0:6.2.7-1.el9_2.2 | 2025-05-12 | redhat |
| redhat | redis:6-8080020250506112946.63b34585 | 2025-05-07 | redhat |
| redhat | redis-0:6.2.6-1.el9_0.2 | 2025-05-06 | redhat |
| redhat | redis:6-8060020250430112137.ad008a3a | 2025-05-06 | redhat |
| redhat | redis:6-8040020250429071832.522a0ee4 | 2025-05-05 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(15 across 12 ecosystems)
Debian:14(3)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| redict | 7.3.0+ds-1 ... 7.3.5+ds-1~bpo12+1 (8 versions) |
| — |
| redis | — |
| — |
| valkey | — |
| — |
Debian:13(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| redis | — |
| — |
| valkey | — |
| — |
Alpine:v3.15(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| redis | — |
| — |
Alpine:v3.18(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| redis | — |
| — |
Alpine:v3.19(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| redis | — |
| — |
Alpine:v3.20(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| valkey | — |
| — |
Alpine:v3.21(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| valkey | — |
| — |
Alpine:v3.22(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| valkey | — |
| — |
Alpine:v3.23(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| valkey | — |
| — |
Alpine:v3.24(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| valkey | — |
| — |
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| redis | 5:6.0.15-1 ... 5:6.0.16-1~bpo11+1 (9 versions) |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| redis | 5:7.0.11-1 ... 5:7.0.15-1~deb12u3 (11 versions) |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(13)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
- Red HatRHBA-2025:8688IMPORTANT2025-04-23
RHBA-2025:8688 — Important
- Red HatRHSA-2025:4441IMPORTANT2025-04-23
RHSA-2025:4441 — Important
- Red HatRHSA-2025:4561IMPORTANT2025-04-23
RHSA-2025:4561 — Important
- Red HatRHSA-2025:4577IMPORTANT2025-04-23
RHSA-2025:4577 — Important
- Red HatRHSA-2025:4607IMPORTANT2025-04-23
RHSA-2025:4607 — Important
- Red HatRHSA-2025:4788IMPORTANT2025-04-23
RHSA-2025:4788 — Important
- Red HatRHSA-2025:4789IMPORTANT2025-04-23
RHSA-2025:4789 — Important
- Red HatRHSA-2025:7429IMPORTANT2025-04-23
RHSA-2025:7429 — Important
- Red HatRHSA-2025:7438IMPORTANT2025-04-23
RHSA-2025:7438 — Important
- Red HatRHSA-2025:7509IMPORTANT2025-04-23
RHSA-2025:7509 — Important
- Red HatRHSA-2025:7538IMPORTANT2025-04-23
RHSA-2025:7538 — Important
- Red HatRHSA-2025:7630IMPORTANT2025-04-23
RHSA-2025:7630 — Important
- Red HatRHSA-2025:7686IMPORTANT2025-04-23
RHSA-2025:7686 — Important
Data Freshness Timeline
(refreshed 9× in last 7d / 40× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 96 of 195 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 4 repeat rows among the latest 100 are merged into the row they repeat. The 99 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-01 16:32 UTCEPSS rescoreEPSS 0.9% · 58th percentile
- 2026-10-31 16:30 UTCEPSS rescoreEPSS 0.9% · 58th percentile
- 2026-10-30 16:32 UTCEPSS rescoreEPSS 0.9% · 58th percentile
- 2026-10-29 16:31 UTCEPSS rescoreEPSS 0.9% · 58th percentile
- 2026-10-28 16:30 UTCEPSS rescoreEPSS 0.9% · 58th percentile
- 2026-10-27 16:30 UTCEPSS rescoreEPSS 0.9% · 58th percentile
- 2026-10-27 12:28 UTCEG score recompute
- 2026-10-27 12:28 UTCVendor advisory
- 2026-10-26 16:29 UTCEPSS rescoreEPSS 0.9% · 58th percentile
- 2026-10-25 16:43 UTCEG score recompute
- 2026-10-25 16:31 UTCEPSS rescoreEPSS 0.9% · 58th percentile
- 2026-10-24 16:30 UTCEPSS rescoreEPSS 0.9% · 58th percentile
- 2026-10-23 16:30 UTCEPSS rescoreEPSS 0.9% · 58th percentile
- 2026-10-22 16:32 UTCEPSS rescoreEPSS 0.9% · 58th percentile
- 2026-10-21 16:30 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-20 16:31 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-19 16:30 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-19 00:50 UTCEG score recompute
- 2026-10-19 00:50 UTCVendor advisory
- 2026-10-18 16:30 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-18 05:46 UTCEG score recompute
- 2026-10-17 16:32 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-16 16:38 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-15 16:30 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-14 16:31 UTCEPSS rescoreEPSS 0.9% · 57th percentile
Show 71 moreShow fewer
- 2026-10-13 16:32 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-12 17:19 UTCEG score recompute
- 2026-10-12 16:32 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-11 20:51 UTCEG score recompute
- 2026-10-11 19:01 UTCEG score recompute
- 2026-10-11 15:41 UTCEG score recompute
- 2026-10-11 13:47 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-08 17:09 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-07 23:46 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-06 15:16 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.9% · 57th percentile
- 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-10-03 14:24 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-10-02 16:40 UTCOSV refresh
- 2026-10-02 16:26 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-10-01 19:48 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-28 13:50 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-26 00:24 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-24 14:02 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-23 13:46 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-22 14:47 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-16 14:06 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-16 05:13 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-15 03:09 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-13 14:13 UTCOSV refresh
- 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-11 14:51 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-11 09:35 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-10 09:33 UTCEPSS rescoreEPSS 0.9% · 56th percentile
- 2026-09-08 21:59 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-09-07 16:00 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-09-06 13:46 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-09-05 15:28 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-09-04 05:05 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-09-01 13:52 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-09-01 04:38 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-30 19:16 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-30 01:21 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-28 21:40 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-27 14:24 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-25 15:39 UTCOSV refresh
- 2026-08-25 13:47 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-23 00:18 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-21 23:48 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-20 22:54 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-18 13:47 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-17 13:46 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-16 14:55 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-16 02:13 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-15 01:29 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-13 21:59 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-12 13:50 UTCEPSS rescoreEPSS 0.9% · 55th percentile
- 2026-08-10 23:59 UTCEPSS rescoreEPSS 0.9% · 54th percentile
- 2026-08-09 13:45 UTCEPSS rescoreEPSS 0.9% · 54th percentile
- 2026-08-09 07:27 UTCOSV refresh
- 2026-08-07 16:26 UTCEPSS rescoreEPSS 0.9% · 54th percentile
- 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.9% · 54th percentile
- 2026-08-05 19:16 UTCEPSS rescoreEPSS 0.9% · 54th percentile
- 2026-08-04 15:09 UTCEPSS rescoreEPSS 0.9% · 54th percentile
- 2026-08-04 10:37 UTCEPSS rescoreEPSS 0.9% · 54th percentile
- 2026-08-03 10:35 UTCEPSS rescoreEPSS 0.9% · 54th percentile
- 2026-08-02 02:25 UTCEPSS rescoreEPSS 0.9% · 54th percentile
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownAlpine:v3.20:valkey
Same vendor
3 shownredhat:RHBA-2025:8262 · redhat:RHBA-2025:8687
Frequently asked(5)
What is CVE-2025-21605?
When was the CVE record for CVE-2025-21605 published?
Is CVE-2025-21605 actively exploited?
What is the CVSS score of CVE-2025-21605?
How do I remediate CVE-2025-21605?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2025-21605
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