CVE-2026-42578

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

1.06% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 62.3% of scored records. A rank, not a probability.

NVD base score

2.9 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/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

NVD analysis status

Modified. NVD last modified this record on 2026-08-13.

Red Hat severity

Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-05-13 17:57Z3 MO AGO

Last updated

2026-08-13 12:04Z22 DAYS AGO

Reserved

2026-04-28

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

Low (CVSS 2.9)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P

Weaknesses

• CWE-113Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')Variant
• CWE-93Improper Neutralization of CRLF Sequences ('CRLF Injection')Base

Data version

5.2

Document digest

ccf4d24a2e12f0e811fc7ff0858d0fe05c6c153e3c1301fa5927cc6f7355d4e8

• github.comhttps://github.com/netty/netty/security/advisories/GHSA-45q3-82m4-75jrx_refsource_CONFIRM
• access.redhat.comhttps://access.redhat.com/security/cve/CVE-2026-42578vdb-entryx_refsource_REDHAT
• bugzilla.redhat.comRHBZ#2477226https://bugzilla.redhat.com/show_bug.cgi?id=2477226issue-trackingx_refsource_REDHAT
• security.access.redhat.comhttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42578.jsonx_sadp-csaf-vex
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:53644vendor-advisoryx_refsource_REDHAT
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:28010vendor-advisoryx_refsource_REDHAT
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:53806vendor-advisoryx_refsource_REDHAT
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:42644vendor-advisoryx_refsource_REDHAT
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:25123vendor-advisoryx_refsource_REDHAT
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:36820vendor-advisoryx_refsource_REDHAT
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:37390vendor-advisoryx_refsource_REDHAT
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:23808vendor-advisoryx_refsource_REDHAT
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:24502vendor-advisoryx_refsource_REDHAT
• access.redhat.comhttps://access.redhat.com/errata/RHSA-2026:54435vendor-advisoryx_refsource_REDHAT