CVE-2021-29390: libjpeg-turbo version 2.0.90 has a heap-based buffer over-read (2 bytes) in decompress_smooth_data in jdcoefct

Routine

HIGH 7.1DOWNGRADEMITIGATE

CVE-2021-29390 is a high-severity flaw (CVSS 7.1) affecting libjpeg-turbo, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

libjpeg-turbo version 2.0.90 has a heap-based buffer over-read (2 bytes) in decompress_smooth_data in jdcoefct.c.

Why this priority

High severity

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

Risk facts

CVSS score	7.1 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.8% (top 43%)
CISA exploited list	No
Weakness	CWE-787
Published	2023-08-22
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: fedoraproject · libjpeg-turbo

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

Am I affected?

Timeline

2023-08-22 19:16 UTCPublished CVE record published
2026-06-17 03:47 UTCUpdated Record last modified

libjpeg-turbo libjpeg-turbo DOWNGRADE

Affected: 2.0.90

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0.90

1. Check installed version

apt-cache policy libjpeg-turbo || rpm -q libjpeg-turbo || libjpeg-turbo --version

2. No fixed release: DOWNGRADE to a release before 2.0.90 (Debian / Ubuntu)

apt-cache madison libjpeg-turbo sudo apt install libjpeg-turbo=<VERSION_BEFORE_2.0.90> sudo apt-mark hold libjpeg-turbo

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

dnf --showduplicates list libjpeg-turbo sudo dnf downgrade libjpeg-turbo-<VERSION_BEFORE_2.0.90> sudo dnf versionlock add libjpeg-turbo

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.

fedoraproject fedora MITIGATE

Affected: 37 · 38 · 39

Fixed in: no fixed release known

Safe to downgrade to: a release before 37

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

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-2021-29390?

libjpeg-turbo: downgrade or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-29390 being exploited?

CVE-2021-29390 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-2021-29390 affect?

CVE-2021-29390 affects libjpeg-turbo, fedora. Severity is high (CVSS 7.1). libjpeg-turbo version 2.0.90 has a heap-based buffer over-read (2 bytes) in decompress_smooth_data in jdcoefct.c.

How urgent is CVE-2021-29390?

Priority 39/100. High severity

Related CVEs

CVE-2023-2804 MEDIUM 6.5 DOWNGRADE A heap-based buffer overflow issue was discovered in libjpeg-turbo in h2v2_merged_upsample_internal() function
CVE-2021-46822 MEDIUM 5.5 UPGRADE The PPM reader in libjpeg-turbo through 2.0.90 mishandles use of tjLoadImage for loading a 16-bit binary PPM f
CVE-2020-35538 MEDIUM 5.5 DOWNGRADE A crafted input file could cause a null pointer dereference in jcopy_sample_rows() when processed by libjpeg-t

References

← Back to latest CVEs