CVE-2021-3696A heap out-of-bounds write may heppen during the handling of Huffman tables in the PNG reader. This may lead to data corruption in the…
- 4.5MediumCVSS base score
- 0.48%Exploitation in 30 daysEPSS · top 58% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A heap out-of-bounds write may heppen during the handling of Huffman tables in the PNG reader. This may lead to data corruption in the heap space. Confidentiality, Integrity and Availablity impact may be considered Low as it's very complex to an attacker control the encoding and positioning of corrupted Huffman entries to achieve results such as arbitrary code execution and/or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.
Timeline
ID reserved
By redhat
- 11 months later
· 11 months later
Published
- 2 years later
· 2 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium4.5 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L |
- EPSS (exploitation in 30 days)
- 0.48% · top 58% of all CVEs (15 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.5.
Affected products
grub2
- affected grub-2.06
References
References3
- https://bugzilla.redhat.com/show_bug.cgi?id=1991686 (opens in a new tab)x_refsource_MISCx_transferred
- GLSA-202209-12 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
- https://security.netapp.com/advisory/ntap-20220930-0001/ (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-26981 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-3696)Record last updated .