CVE-2020-12135: bson before 0.8 incorrectly uses int rather than size_t for many variables, parameters, and return values

Q: How do I fix CVE-2020-12135?

whoopsie: upgrade to newer than 0.2.69; c driver: upgrade to 0.8. Exact commands for each OS are on this page.

Q: Is CVE-2020-12135 being exploited?

CVE-2020-12135 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2020-12135 affect?

CVE-2020-12135 affects whoopsie, c driver. Severity is medium (CVSS 5.5). bson before 0.8 incorrectly uses int rather than size_t for many variables, parameters, and return values. In particular, the bson_ensure_space() parameter bytesNeeded could have an integer overflow via properly constructed bson input.

Q: How urgent is CVE-2020-12135?

Priority 41/100. Public exploit reference

This month

MEDIUM 5.5UPGRADEUPGRADE

CVE-2020-12135 is a medium-severity flaw (CVSS 5.5) affecting whoopsie, c driver. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

bson before 0.8 incorrectly uses int rather than size_t for many variables, parameters, and return values. In particular, the bson_ensure_space() parameter bytesNeeded could have an integer overflow via properly constructed bson input.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.2% (top 33%)
CISA exploited list	No
Weakness	CWE-190
Published	2020-04-24
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: mongodb · whoopsie project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-04-24 01:15 UTCPublished CVE record published
2026-06-17 02:51 UTCUpdated Record last modified

whoopsie project whoopsie UPGRADE

Affected: <= 0.2.69

Fixed in: newer than 0.2.69

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy whoopsie || rpm -q whoopsie || whoopsie --version

2. UPGRADE to newer than 0.2.69 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade whoopsie

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade whoopsie

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

mongodb c driver UPGRADE

Affected: < 0.8

Fixed in: 0.8

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy c-driver || rpm -q c-driver || c-driver --version

2. UPGRADE to 0.8 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade c-driver

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade c-driver

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2020-12135?

whoopsie: upgrade to newer than 0.2.69; c driver: upgrade to 0.8. Exact commands for each OS are on this page.

Is CVE-2020-12135 being exploited?

CVE-2020-12135 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-2020-12135 affect?

CVE-2020-12135 affects whoopsie, c driver. Severity is medium (CVSS 5.5). bson before 0.8 incorrectly uses int rather than size_t for many variables, parameters, and return values. In particular, the bson_ensure_space() parameter bytesNeeded could have an integer overflow via properly constructed bson input.

How urgent is CVE-2020-12135?

Priority 41/100. Public exploit reference

Software pages

MongoDB vulnerabilities

Related CVEs

CVE-2020-15570 MEDIUM 5.5 UPGRADE The parse_report() function in whoopsie.c in Whoopsie through 0.2.69 mishandles memory allocation failures, wh
CVE-2020-11937 MEDIUM 5.5 DOWNGRADE In whoopsie, parse_report() from whoopsie.c allows a local attacker to cause a denial of service via a crafted
CVE-2019-11484 MEDIUM 6.3 MITIGATE MITIGATE Kevin Backhouse discovered an integer overflow in bson_ensure_space, as used in whoopsie.

References

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