CVE-2026-6753: Incorrect boundary conditions in the WebRTC component
Modified
AliasesUBUNTU-CVE-2026-6753DEBIAN-CVE-2026-6753CGA-gvfh-ghpf-93f2CGA-vxjg-w55h-cxhmCGA-p8cp-34qh-r68mCGA-v3q7-qch4-mghh
Published 21-04-2026Last modified 15-07-2026
Vulnerability summary
CVE-2026-6753 is a high (CVSS 7.3) vulnerability in mozilla firefox. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 38.7% of scored vulnerabilities.
CVSS score
7.3/10
010
High · v3.1 (CVE.org)EPSS score
0.46%
0%100%
Low · +0.15 pp in 30 daysKEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 32 · Related 4MGASA-2026-0124MGASA-2026-0125OPENSUSE-SU-2026:10610-1OPENSUSE-SU-2026:10626-1OPENSUSE-SU-2026:11373-1RHSA-2026:10757RHSA-2026:10766RHSA-2026:10767RHSA-2026:12285RHSA-2026:13537RHSA-2026:15892RHSA-2026:17477RHSA-2026:17687RHSA-2026:17688RHSA-2026:17689RHSA-2026:17690RHSA-2026:19041RHSA-2026:19131RHSA-2026:19201RHSA-2026:19348RHSA-2026:19461RHSA-2026:19462RHSA-2026:19463RHSA-2026:19464RHSA-2026:19465RHSA-2026:19466RHSA-2026:19467RHSA-2026:19468RHSA-2026:19469RHSA-2026:19542RHSA-2026:19655RHSA-2026:19704CGA-H63F-JR6P-QX7C
Timeline
- 21-04-2026PublishedVulnerability first disclosed.
- 15-07-2026Last modifiedVulnerability information updated.
Description
Incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
CVSS metrics
4 scores · 4 sources · 1 versionHigh 7.3Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:LSources4 sources · 7.3–7.5
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HDiffers
- OSV · DebianEcosystem advisory · calculated7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- NVDNIST7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS trend
Probability
0.46%
Chance of exploitation in the next 30 days
Percentile
39%
Versus all other CVEs
30-day change
Increase +0.15 pp
From 0.31% on 22-09-2026
22-09-202622-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferThe product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
- CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.
Affected systems
Ubuntu8 products
- mozjs102All versions (No fix recorded)
- mozjs115All versions (No fix recorded)
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
- mozjs68All versions (No fix recorded)
Chainguard2 products
- firefox< 140.10-r0
- firefox-esr< 140.10-r0
Debian2 products
- firefox-esr< 140.10.0esr-1~deb12u1 | < 140.10.0esr-1~deb13u1 | < 140.10.0esr-1
- thunderbird< 1:140.10.0esr-1~deb12u1 | < 1:140.10.0esr-1~deb13u1 | < 1:140.10.0esr-1
Mozilla2 products
- firefox< 140.10.0 | < 150.0
- thunderbird≥ 140.0, < 140.10.0
Wolfi1 product
- firefox< 140.10-r0
5 vendors · 15 products
References
40 links- bugzilla.mozilla.org/show_bug.cgi?id=2027501Permissions Required
- www.mozilla.org/security/advisories/mfsa2026-30/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-32/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-33/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-34/Vendor Advisory
