CVE-2006-0635: Tiny C Compiler (TCC) 0.9.23 (aka TinyCC) evaluates the "i>sizeof(int)" expression to false when i equals -1,

Routine

MEDIUM 4.6DOWNGRADE

CVE-2006-0635 is a medium-severity flaw (CVSS 4.6) affecting tiny c compiler. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Tiny C Compiler (TCC) 0.9.23 (aka TinyCC) evaluates the "i>sizeof(int)" expression to false when i equals -1, which might introduce integer overflow vulnerabilities into applications that could be exploited by context-dependent attackers.

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	4.6 (Medium)
EPSS exploit chance	0.4% (top 71%)
CISA exploited list	No
Published	2006-02-10
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: fabrice bellard

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2006-02-10 11:02 UTCPublished CVE record published
2026-06-16 22:20 UTCUpdated Record last modified

fabrice bellard tiny c compiler DOWNGRADE

Affected: 0.9.23

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.9.23

1. Check installed version

apt-cache policy tiny-c-compiler || rpm -q tiny-c-compiler || tiny-c-compiler --version

2. No fixed release: DOWNGRADE to a release before 0.9.23 (Debian / Ubuntu)

apt-cache madison tiny-c-compiler sudo apt install tiny-c-compiler=<VERSION_BEFORE_0.9.23> sudo apt-mark hold tiny-c-compiler

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list tiny-c-compiler sudo dnf downgrade tiny-c-compiler-<VERSION_BEFORE_0.9.23> sudo dnf versionlock add tiny-c-compiler

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2006-0635?

tiny c compiler: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2006-0635 being exploited?

CVE-2006-0635 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2006-0635 affect?

CVE-2006-0635 affects tiny c compiler. Severity is medium (CVSS 4.6). Tiny C Compiler (TCC) 0.9.23 (aka TinyCC) evaluates the "i>sizeof(int)" expression to false when i equals -1, which might introduce integer overflow vulnerabilities into applications that could be exploited by context-dependent attackers.

How urgent is CVE-2006-0635?

Priority 23/100. No elevated risk signals yet.

References

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