In libexpat before 2.7.4, the doContent function does not properly determine the buffer size...

Description

In libexpat before 2.7.4, the doContent function does not properly determine the buffer size bufSize because there is no integer overflow check for tag buffer reallocation.

Basic information

Type
unreviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Source code
Not specified
Published (advisory)
2026-01-30 09:30:55 UTC
Updated
2026-06-02 15:32:59 UTC
NVD published
2026-01-30

EPSS Score

Score Percentile
0.01% 0.61%

CVSS Scores

Base score Version Severity Vector
6.9 3.1
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.

Identifiers

CWEs

CWE id Name
CWE-190 Integer Overflow or Wraparound

References

cvelogic Threat Intelligence