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Public proof of conceptFix available

CVE-2023-45288

A public proof of concept exists; no exploitation attested.

  • Published2024-04-04
  • Fixed in1.22.2 · 1.21.9

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

An attacker may cause an HTTP/2 endpoint to read arbitrary amounts of header data by sending an excessive number of CONTINUATION frames. Maintaining HPACK state requires parsing and processing all HEADERS and CONTINUATION frames on a connection. When a request's headers exceed MaxHeaderBytes, no memory is allocated to store the excess headers, but they are still parsed. This permits an attacker to cause an HTTP/2 endpoint to read arbitrary amounts of header data, all associated with a request which is going to be rejected. These headers can include Huffman-encoded data which is significantly more expensive for the receiver to decode than for an attacker to send. The fix sets a limit on the amount of excess header frames we will process before closing a connection.

Timeline

dates in UTC
  1. 2024-04-0421:15CVE publishedNVD
  2. 2026-10-2319:23First public proof of conceptPoC-in-GitHub
  3. 2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2023-45288?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-45288?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

CISA-ADP
Go standard library net\/http
BranchAffectedFixed in
1.22≥ 1.22.0-0, < 1.22.21.22.2
1.21< 1.21.91.21.9
Golang http2
BranchAffectedFixed in
0.23< 0.23.00.23.0

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • RHSA-2026:83627 Red Hat Product Security64 products fixed

    Red Hat Security Advisory: Red Hat OpenShift Data Foundation 4.14.40 security, enhancement & bug fix update

  • RHSA-2025:8274 Red Hat Product Security35 products fixed

    Red Hat Security Advisory: Errata Advisory for Red Hat OpenShift GitOps v1.14.4 security update

  • RHSA-2025:7753 Red Hat Product Security35 products fixed

    Red Hat Security Advisory: Errata Advisory for Red Hat OpenShift GitOps v1.15.2 security update

  • RHSA-2025:4240 Red Hat Product Security18 products fixed

    Red Hat Security Advisory: Updated 6.1 container image is now available in the Red Hat Ecosystem Catalog.

  • RHSA-2024:6122 Red Hat Product Security662 products fixed

    Red Hat Security Advisory: OpenShift Container Platform 4.18.1 bug fix and security update

  • RHBA-2025:1772 Red Hat Product Security20 products fixed

    Red Hat Bug Fix Advisory: Updated 7.1 container image is now available in the Red Hat Ecosystem Catalog

13 more advisories

Full record on NVD

Fix

  1. Update Go standard library net\/http to 1.22.2 · 1.21.9
  2. Vendor fix Red Hat Product Security RHSA-2026:83627 · 64 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://docs.redhat.com/en/documentation/red_hat_openshift_data_foundation/4.14/html/updating_openshift_data_foundation/updating-ocs-…
  3. Vendor fix Red Hat Product Security RHSA-2025:8274 · 35 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
  4. Vendor fix Red Hat Product Security RHSA-2025:4240 · 18 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/2789521 For supported configurations, refer to: https://access.redhat.com/articles/1548993
  5. Vendor fix Red Hat Product Security RHSA-2024:6122 · 662 productsFor OpenShift Container Platform 4.18 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this asynchronous errata update: https://docs.openshift.com/container-platform/4.18/release_notes/o…
  6. Vendor fix Red Hat Product Security RHSA-2025:0832 · 1 productFor OpenShift Container Platform 4.12 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this asynchronous errata update: https://docs.openshift.com/container-platform/4.12/release_notes/ocp-4-1…
  7. Vendor fix Red Hat Product Security RHSA-2025:0536 · 8 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. The steps to apply the upgraded images are different depending on the installation plan approval policy you used when installing the cert-manager Operator for Red Hat OpenShift. - If the…

Detection

read 2026-10-23 19:23 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
1 repository, unverifiedhex0punk/cont-flood-poc
PoC-in-GitHub

Sources

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2024-04-04
Last Modified
2026-06-17
NVD status
Deferred

Frequently asked questions

What is CVE-2023-45288?

An attacker may cause an HTTP/2 endpoint to read arbitrary amounts of header data by sending an excessive number of CONTINUATION frames. Maintaining HPACK state requires parsing and processing all HEADERS and CONTINUATION frames on a connection. When a request's headers exceed MaxHeaderBytes, no memory is allocated to store the excess headers, but they are still parsed. This permits an attacker to cause an HTTP/2 endpoint to read arbitrary amounts of header data, all associated with a request which is going to be rejected. These headers can include Huffman-encoded data which is significantly more expensive for the receiver to decode than for an attacker to send. The fix sets a limit on the amount of excess header frames we will process before closing a connection.

Is CVE-2023-45288 actively exploited?

Active exploitation of CVE-2023-45288 has not been confirmed. Its EPSS score was 92.0% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-45288?

CVE-2023-45288 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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