h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. The configuration directives provided by the headers handler allows users to modify the response headers being sent by h2o. The configuration file of h2o has scopes, and the inner scopes (e.g., path level) are expected to inherit the configuration defined in outer scopes (e.g., global level). However, if a header directive is used in the inner scope, all the definition in outer scopes are ignored. This can lead to headers not being modified as expected. Depending on the headers being added or removed unexpectedly, this behavior could lead to unexpected client behavior. This vulnerability is fixed in commit 123f5e2b65dcdba8f7ef659a00d24bd1249141be.
CVE-2024-25622
“—” beside the score: it is equal to NVD's CVSS score.
This low-severity CVE scores 3.1 under NVD CVSS v3. EPSS exploit probability: 0.5% (40th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2024-22943 (ENISA EUVD)Source: ENISA EUVD
- Lower severity and no public exploit yet
A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).
- CVSS v3
- 3.1
- EG Score
- 3.1LOWmedium confidence
- EG Risk
- 14EG Risk 14/100
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)Severity31% × 45%Impact severity (EG Severity): CVSS 3.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.5% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.Exploitation none (CISA Vulnrichment) · Automatable no (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 referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule. - EPSS PROB
- 0.5%
- EPSS %ILE
- 40th
- 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 (3.1): severity, escalated by confirmed exploitation. This CVE's 3.1 is its impact severity (EG Severity), not escalated.
- EG Severity
- 3.1 LOWCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- 0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.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 every mission impact level.
A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it; until one is applied, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule.
Exploitation none (CISA Vulnrichment) · Automatable no (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says. In the directive's words, “Fix on system upgrade” means that, “unless conditions change”, the vulnerability “should be remediated the next time the vulnerable asset receives a scheduled major upgrade or rebuild”: its timelines are “dynamic as facts change”, and a KEV listing shortens them.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (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
October 11, 2024
Last Modified
November 12, 2024
References (3)
- security-advisories@githubhttps://github.com/h2o/h2o/commit/123f5e2b65dcdba8f7ef659a00d24bd1249141bePatch
- security-advisories@githubhttps://github.com/h2o/h2o/issues/3332Issue Tracking
- security-advisories@githubhttps://github.com/h2o/h2o/security/advisories/GHSA-5m7v-cj65-h6pjExploit · Vendor Advisory
Affected Packages
(2 across 2 ecosystems)
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| h2o | 2.2.5+dfsg2-10 ... 2.2.5+dfsg2-9 (10 versions) |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| h2o | 2.2.5+dfsg2-10 ... 2.2.5+dfsg2-9 (7 versions) |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 36× 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 97 of 207 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. 3 repeat rows among the latest 100 are merged into the row they repeat. The 110 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-01 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-31 16:30 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-30 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-29 16:30 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-28 16:29 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-27 16:29 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-26 16:29 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-25 17:16 UTCEG score recompute
- 2026-10-25 16:30 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-25 09:15 UTCEG score recompute
- 2026-10-24 16:30 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-23 16:29 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-22 16:31 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-21 16:29 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-20 16:30 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-19 16:29 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-18 16:29 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-18 07:24 UTCEG score recompute
- 2026-10-17 16:30 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-16 16:36 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-15 16:29 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-14 16:30 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-13 16:30 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-12 18:00 UTCEG score recompute
- 2026-10-12 16:31 UTCEPSS rescoreEPSS 0.5% · 38th percentile
Show 72 moreShow fewer
- 2026-10-11 21:24 UTCEG score recompute
- 2026-10-11 16:18 UTCEG score recompute
- 2026-10-11 13:45 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-10 19:58 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-10 11:33 UTCOSV refresh
- 2026-10-09 20:05 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-08 17:07 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-07 23:46 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-06 15:15 UTCEPSS rescoreEPSS 0.5% · 38th percentile
- 2026-10-05 17:41 UTCEPSS rescoreEPSS 0.5% · 37th percentile
- 2026-10-04 23:20 UTCEPSS rescoreEPSS 0.5% · 37th percentile
- 2026-10-03 14:23 UTCEPSS rescoreEPSS 0.5% · 37th percentile
- 2026-10-01 19:48 UTCEPSS rescoreEPSS 0.5% · 37th percentile
- 2026-09-30 16:59 UTCEG score recompute
- 2026-09-30 15:01 UTCEPSS rescoreEPSS 0.5% · 37th percentile
- 2026-09-29 15:17 UTCEPSS rescoreEPSS 0.5% · 37th percentile
- 2026-09-28 13:49 UTCEPSS rescoreEPSS 0.5% · 37th percentile
- 2026-09-24 14:01 UTCEPSS rescoreEPSS 0.5% · 37th percentile
- 2026-09-23 13:46 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-20 21:26 UTCOSV refresh
- 2026-09-20 20:14 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-16 14:06 UTCEPSS rescoreEPSS 0.4% · 37th percentile
- 2026-09-16 05:11 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-15 03:08 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-13 16:45 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-12 14:59 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-11 14:51 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-11 09:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-08 21:58 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-07 15:59 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-06 13:46 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-05 15:26 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-04 13:58 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-04 05:05 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-02 14:10 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-09-01 20:57 UTCOSV refresh
- 2026-09-01 13:52 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-30 19:15 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-30 01:20 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-28 21:39 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-27 14:23 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-26 14:44 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-25 13:47 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-23 00:17 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-21 23:47 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-20 22:53 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-19 17:02 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-18 13:46 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-17 13:45 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-16 14:54 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-16 02:12 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-15 22:37 UTCOSV refresh
- 2026-08-15 01:28 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-13 21:58 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-12 13:49 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-11 13:40 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-09 13:45 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-08 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-06 13:45 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-05 19:15 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-04 15:08 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-04 10:36 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-03 10:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-02 02:25 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-08-01 04:14 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-07-31 16:12 UTCOSV refresh
- 2026-07-30 16:26 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-07-30 01:29 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-07-28 15:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-07-27 14:11 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-07-26 14:53 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-07-25 14:16 UTCEPSS rescoreEPSS 0.4% · 36th percentile
Related CVEs(same product + same CWE)
Same product
10 shownDebian:11:h2o
- CVE-2018-0608EG 9.8EPSS p90CRITICAL
- CVE-2023-44487NVD 7.5EG 9.0 KEVEPSS p100CRITICAL
- CVE-2019-9515NVD 7.5EG 9.0EPSS p100CRITICAL
- CVE-2019-9512NVD 7.5EG 9.0EPSS p100CRITICAL
- CVE-2019-9514NVD 7.5EG 8.9EPSS p100HIGH
- CVE-2026-54340EG 7.5HIGH
- CVE-2026-44453EG 7.5HIGH
- CVE-2026-55213EG 7.5HIGH
- CVE-2025-8671EG 7.5EPSS p90HIGH
- CVE-2017-10908EG 7.5EPSS p90HIGH
Frequently asked(5)
What is CVE-2024-25622?
When was the CVE record for CVE-2024-25622 published?
Is CVE-2024-25622 actively exploited?
What is the CVSS score of CVE-2024-25622?
How do I remediate CVE-2024-25622?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2024-25622
Is Your Infrastructure Affected by CVE-2024-25622?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.