GNU libidn before 1.44 is prone to out-of-bounds reads of uninitialized memory in the ToUnicode...

Description

GNU libidn before 1.44 is prone to out-of-bounds reads of uninitialized memory in the ToUnicode APIs because of mishandling in idna_to_unicode_internal. The affected code is not present in libidn2.

Basic information

Type
unreviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Source code
Not specified
Published (advisory)
2026-06-23 18:31:45 UTC
Updated
2026-06-23 18:31:56 UTC
NVD published
2026-06-23

EPSS Score

Score Percentile
0.12% 1.95%

CVSS Scores

Base score Version Severity Vector
4.0 3.1
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.

Identifiers

CWEs

CWE id Name
CWE-1284 Improper Validation of Specified Quantity in Input

References

cvelogic Threat Intelligence