CVE-2026-56289

Process hang via unchecked hunk line offset

Published Jul 9, 2026 · Updated Jul 9, 2026

Denial of service in GNU patch 2.8.0 and earlier allows context-dependent attackers to hang the process via a crafted unified-diff file. The unified-diff hunk parser accepts an extremely large target line number and loops indefinitely while searching for that requested position. Processing an attacker-supplied patch consumes excessive CPU and requires manual termination, without reported data disclosure or modification.

CVSS severity4.6
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in GNU patch 2.8.0 and earlier allows context-dependent attackers to hang the process via a crafted unified-diff file. The unified-diff hunk parser accepts an extremely large target line number and loops indefinitely while searching for that requested position. Processing an attacker-supplied patch consumes excessive CPU and requires manual termination, without reported data disclosure or modification.

The record

CVE
CVE-2026-56289
Published
Jul 9, 2026
Updated
Jul 9, 2026
Vendor
The GnuPG Project
Product
patch
Classifications
CWE-835, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.8.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The GnuPG Project · patchversion=0 <=2.8.0

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.6CERT.PLCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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