BIG-HKSCS decoding hang on crafted input
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- No fix listed
- Who is exposed
- Not reported
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed per the CVSS vector, reachable over the network without a login · Data gap: No advisory context yet
- Reach20/20Affects glibc (software on nearly every server, desktop or phone)
- Severity5.9/10CVSS 5.9
- No patch5/5No patch listed yet
What would change the score
- Would score about 93 if added to CISA KEV
- Would score about 88 if CISA's SSVC rates exploitation active
- Would score about 53 if advisories confirm default setups are exposed
CVE-2026-122054 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.9 (medium) and affects glibc; no fixed version is listed yet.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 48/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The BIG-HKSCS character converter in the GNU C Library, which applications use through functions such as iconv, can be made to stop making progress and hang when it receives crafted input. An attacker can trigger this remotely, without logging in, by supplying that input to an affected application, which then stalls.
Read the original description
Converting crafted BIG-HKSCS input to UCS-4 or the internal wide character encoding, for example with iconv, in the GNU C Library version 2.18 through 2.31 may result in the converter making no progress, causing the calling application to hang.
Timeline
- CVE published
- First seen by cve.now
- Record last updated
Affected versions
- The GNU C Library glibc
From 2.18 · through 2.31
Evidence 3
- Advisory
- Report
- Link
Corrections
None so far.
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Questions about CVE-2026-122054
Is CVE-2026-122054 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-122054?
glibc: from 2.18 through 2.31.Source: cve.now feed data