CVE Intelligence
Medium Denial of service

CVE-2024-28182 — Reading unbounded number of HTTP/2 CONTINUATION frames to cause excessive CPU usage

nghttp2 is an implementation of the Hypertext Transfer Protocol version 2 in C. The nghttp2 library prior to version 1.61.0 keeps reading the unbounded number of HTTP/2 CONTINUATION frames even after a stream is reset to keep HPACK context in sync. This causes excessive CPU usage to decode HPACK stream. nghttp2 v1.61.0 mitigates this vulnerability by limiting the number of CONTINUATION frames it accepts per stream. There is no workaround for this vulnerability.

Published Apr 4, 2024 · Updated Oct 14, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 85% (30-day exploitation probability)+15
  • Technical severity (medium)+3
  • Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
84.96%
ahead of 100% of scored CVEs · Oct 14, 2026
Affects
Debian
Debian Linux and 2 more
CVSS base
5.3
Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — github.com (NIST National Vulnerability Database)
  • Documented patch — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Fedoraproject Fedora, Nghttp2 Nghttp2).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
  5. Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Debian Debian Linux version 10.0version 11.0 Vulnerable NIST National Vulnerability Database
Fedoraproject Fedora version 38version 39version 40 Vulnerable NIST National Vulnerability Database
Nghttp2 Nghttp2 < 1.61.0 Vulnerable NIST National Vulnerability Database
Nghttp2 Nghttp2 version < 1.61.0 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
5.3 CVSS 3.1 Medium 3.9 1.4 security-advisories@github.com via NIST National Vulnerability Database
5.3 CVSS 3.1 Medium — — GitHub_M via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-770 · Allocation of Resources Without Limits or Throttling

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Track CPU/memory spikes and availability drops correlated with request patterns.
web/proxy/WAF logsnetwork IDS/IPSresource metrics

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · nghttp2/nghttp2
    Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 14, 2026
  • Fix documented
    Oct 14, 2026 · NIST National Vulnerability Database
  • Affected products added · nghttp2/nghttp2, debian/debian linux, fedoraproject/fedora
    Oct 14, 2026 · NIST National Vulnerability Database
  • CVSS changed · 5.3
    Oct 14, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 14, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 14, 2026 · Alertas do Telegram
  • 2024
  • CVE published
    Apr 4, 2024 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 1× References added · Oct 14, 2026 – Oct 14, 2026
  • 1× Official description updated · Oct 14, 2026 – Oct 14, 2026

References

12 on the record

Elsewhere on this site

Debian
every CVE for this vendor
Denial of service
same class
CWE-770
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-12996 A use-after-free in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote... Jul 30, 2026
  • CVE-2026-58055 nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length Jun 27, 2026
  • CVE-2026-56968 Use of Uninitialized Resource in Gnu Sasl Jun 23, 2026
  • CVE-2026-54231 Abrt: unsanitized systemd journal content written to dump directory files enables content injection Jun 13, 2026
  • CVE-2026-54230 Abrt: event handler scripts follow symlinks when writing output files, allowing arbitrary file overwrites Jun 13, 2026
  • CVE-2026-49975 Apache HTTP Server: mod_http2 denial of service Jun 8, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2024-28182 is "Reading unbounded number of HTTP/2 CONTINUATION frames to cause excessive CPU usage", rated Medium. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. EPSS 84.96% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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