CVE-2026-77117Network attack vector

Application hang via uncleared pending decoder state

Published Sep 15, 2026 · Updated Sep 15, 2026

Infinite-loop denial of service in glibc 2.3 through 2.44 allows remote attackers to hang calling applications via crafted SHIFT_JISX0213 input. The SHIFT_JISX0213 decoder in iconvdata/shift_jisx0213.c emits a saved second code point after E2BIG but fails to clear the pending conversion state, so retries repeat output without consuming input. Exploitation requires attacker-controlled input, the uncommon encoding, a buffer split between paired code points, and an application that retries conversion; only that caller hangs.

CVSS severity5.9
Medium
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Infinite-loop denial of service in glibc 2.3 through 2.44 allows remote attackers to hang calling applications via crafted SHIFT_JISX0213 input. The SHIFT_JISX0213 decoder in iconvdata/shift_jisx0213.c emits a saved second code point after E2BIG but fails to clear the pending conversion state, so retries repeat output without consuming input. Exploitation requires attacker-controlled input, the uncommon encoding, a buffer split between paired code points, and an application that retries conversion; only that caller hangs.

The record

CVE
CVE-2026-77117
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
The GnuPG Project
Product
glibc
Classifications
CWE-835, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 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=2.3 <=2.44

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The GnuPG Project · glibcversion=2.3 <=2.44

Published CVSS scores

5.9Red HatCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
5.1Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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