CVE & CISA-KEV CatalogNVD
CVE-2026-78663
HIGH7.5
CVSS v3
Description
The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.
How to fix
Remediation Available
golang-1.26Debian
Fixed in:1.26.9-1CVE-2026-78663
golang-1.27Debian
Fixed in:1.27.2-1CVE-2026-78663
golang-golang-x-netDebian
Fixed in:1:0.60.0-1CVE-2026-78663
golang.org/x/netGo
Fixed in:0.60.0GO-2026-6612
stdlibGo
Fixed in:1.26.9GO-2026-6612
delve-0:1.26.1Red Hat / RHEL
Fixed in:1.module+el8.4.0+25181+7ce5b91c.x86_64::go-toolset:rhel8RHSA-2026:90994
Fixed in:1.module+el8.10.0+24516+40554724.ppc64le::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+24516+40554724.aarch64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+24516+40554724.src::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.6.0+24782+a062e766.src::go-toolset:rhel8RHSA-2026:87246
Fixed in:1.module+el8.8.0+24781+86ad105d.src::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+24516+40554724.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.4.0+25181+7ce5b91c.src::go-toolset:rhel8RHSA-2026:90994
delve-0:1.26.1Rocky
Fixed in:1.module+el8.10.0+24516+40554724.aarch64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.4.0+25181+7ce5b91c.src::go-toolset:rhel8RHSA-2026:90994
Fixed in:1.module+el8.6.0+24782+a062e766.src::go-toolset:rhel8RHSA-2026:87246
Fixed in:1.module+el8.4.0+25181+7ce5b91c.x86_64::go-toolset:rhel8RHSA-2026:90994
Fixed in:1.module+el8.10.0+24516+40554724.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.8.0+24781+86ad105d.src::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.8.0+24781+86ad105d.x86_64::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+24516+40554724.src::go-toolset:rhel8RHSA-2026:86203
delve-debuginfo-0:1.26.1Rocky
Fixed in:1.module+el8.4.0+25181+7ce5b91c.x86_64::go-toolset:rhel8RHSA-2026:90994
Fixed in:1.module+el8.10.0+24516+40554724.aarch64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+24516+40554724.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+24516+40554724.ppc64le::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.8.0+24781+86ad105d.ppc64le::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.8.0+24781+86ad105d.x86_64::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.6.0+24782+a062e766.x86_64::go-toolset:rhel8RHSA-2026:87246
delve-debuginfo-0:1.26.1Red Hat / RHEL
Fixed in:1.module+el8.10.0+24516+40554724.aarch64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.4.0+25181+7ce5b91c.x86_64::go-toolset:rhel8RHSA-2026:90994
Fixed in:1.module+el8.8.0+24781+86ad105d.ppc64le::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.8.0+24781+86ad105d.x86_64::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+24516+40554724.ppc64le::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+24516+40554724.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.6.0+24782+a062e766.x86_64::go-toolset:rhel8RHSA-2026:87246
delve-debugsource-0:1.26.1Rocky
Fixed in:1.module+el8.10.0+24516+40554724.aarch64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.6.0+24782+a062e766.x86_64::go-toolset:rhel8RHSA-2026:87246
Fixed in:1.module+el8.8.0+24781+86ad105d.ppc64le::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.4.0+25181+7ce5b91c.x86_64::go-toolset:rhel8RHSA-2026:90994
Fixed in:1.module+el8.10.0+24516+40554724.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.8.0+24781+86ad105d.x86_64::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+24516+40554724.ppc64le::go-toolset:rhel8RHSA-2026:86203
delve-debugsource-0:1.26.1Red Hat / RHEL
Fixed in:1.module+el8.6.0+24782+a062e766.x86_64::go-toolset:rhel8RHSA-2026:87246
Fixed in:1.module+el8.8.0+24781+86ad105d.x86_64::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+24516+40554724.ppc64le::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+24516+40554724.aarch64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.4.0+25181+7ce5b91c.x86_64::go-toolset:rhel8RHSA-2026:90994
Fixed in:1.module+el8.10.0+24516+40554724.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.8.0+24781+86ad105d.ppc64le::go-toolset:rhel8RHSA-2026:87245
go-toolsetRocky
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
go-toolsetRed Hat / RHEL
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
go-toolset-0:1.26.10Red Hat / RHEL
Fixed in:1.module+el8.10.0+25107+6b50279c.ppc64le::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+25107+6b50279c.s390x::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+25107+6b50279c.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.8.0+25113+a148ecc0.x86_64::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+25107+6b50279c.aarch64::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.8.0+25113+a148ecc0.ppc64le::go-toolset:rhel8RHSA-2026:87245
Fixed in:2.module+el8.4.0+25201+9a419e96.x86_64::go-toolset:rhel8RHSA-2026:90994
Fixed in:4.module+el8.6.0+25114+90ecdb41.x86_64::go-toolset:rhel8RHSA-2026:87246
go-toolset-0:1.26.10Rocky
Fixed in:1.module+el8.10.0+25107+6b50279c.s390x::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+25107+6b50279c.ppc64le::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.6.0+25114+90ecdb41.x86_64::go-toolset:rhel8RHSA-2026:87246
Fixed in:4.module+el8.8.0+25113+a148ecc0.ppc64le::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+25107+6b50279c.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.8.0+25113+a148ecc0.x86_64::go-toolset:rhel8RHSA-2026:87245
Fixed in:2.module+el8.4.0+25201+9a419e96.x86_64::go-toolset:rhel8RHSA-2026:90994
Fixed in:1.module+el8.10.0+25107+6b50279c.aarch64::go-toolset:rhel8RHSA-2026:86203
golangRed Hat / RHEL
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
golangRocky
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
golang-0:1.26.10Red Hat / RHEL
Fixed in:1.module+el8.10.0+25107+6b50279c.ppc64le::go-toolset:rhel8RHSA-2026:86203
Fixed in:2.module+el8.4.0+25201+9a419e96.x86_64::go-toolset:rhel8RHSA-2026:90994
Fixed in:1.module+el8.10.0+25107+6b50279c.src::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+25107+6b50279c.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.6.0+25114+90ecdb41.x86_64::go-toolset:rhel8RHSA-2026:87246
Fixed in:2.module+el8.4.0+25201+9a419e96.src::go-toolset:rhel8RHSA-2026:90994
Fixed in:4.module+el8.6.0+25114+90ecdb41.src::go-toolset:rhel8RHSA-2026:87246
Fixed in:1.module+el8.10.0+25107+6b50279c.s390x::go-toolset:rhel8RHSA-2026:86203
golang-0:1.26.10Rocky
Fixed in:4.module+el8.8.0+25113+a148ecc0.src::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+25107+6b50279c.s390x::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.8.0+25113+a148ecc0.ppc64le::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+25107+6b50279c.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.6.0+25114+90ecdb41.x86_64::go-toolset:rhel8RHSA-2026:87246
Fixed in:4.module+el8.6.0+25114+90ecdb41.src::go-toolset:rhel8RHSA-2026:87246
Fixed in:4.module+el8.8.0+25113+a148ecc0.x86_64::go-toolset:rhel8RHSA-2026:87245
Fixed in:2.module+el8.4.0+25201+9a419e96.src::go-toolset:rhel8RHSA-2026:90994
golang-binRocky
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
golang-binRed Hat / RHEL
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
golang-bin-0:1.26.10Rocky
Fixed in:4.module+el8.8.0+25113+a148ecc0.ppc64le::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+25107+6b50279c.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.8.0+25113+a148ecc0.x86_64::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+25107+6b50279c.ppc64le::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+25107+6b50279c.s390x::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+25107+6b50279c.aarch64::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.6.0+25114+90ecdb41.x86_64::go-toolset:rhel8RHSA-2026:87246
Fixed in:2.module+el8.4.0+25201+9a419e96.x86_64::go-toolset:rhel8RHSA-2026:90994
golang-bin-0:1.26.10Red Hat / RHEL
Fixed in:4.module+el8.8.0+25113+a148ecc0.x86_64::go-toolset:rhel8RHSA-2026:87245
Fixed in:1.module+el8.10.0+25107+6b50279c.x86_64::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+25107+6b50279c.ppc64le::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.6.0+25114+90ecdb41.x86_64::go-toolset:rhel8RHSA-2026:87246
Fixed in:2.module+el8.4.0+25201+9a419e96.x86_64::go-toolset:rhel8RHSA-2026:90994
Fixed in:1.module+el8.10.0+25107+6b50279c.s390x::go-toolset:rhel8RHSA-2026:86203
Fixed in:1.module+el8.10.0+25107+6b50279c.aarch64::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.8.0+25113+a148ecc0.ppc64le::go-toolset:rhel8RHSA-2026:87245
golang-docsRocky
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el9_4RHSA-2026:87042
Fixed in:0:1.26.10-1.el9_8RHSA-2026:86196
Fixed in:0:1.26.10-1.el9_2RHSA-2026:87041
Fixed in:0:1.26.10-1.el9_6RHSA-2026:87043
golang-docsRed Hat / RHEL
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el9_8RHSA-2026:86196
Fixed in:0:1.26.10-1.el9_4RHSA-2026:87042
Fixed in:0:1.26.10-1.el9_2RHSA-2026:87041
Fixed in:0:1.26.10-1.el9_6RHSA-2026:87043
golang-docs-0:1.26.10Rocky
Fixed in:4.module+el8.6.0+25114+90ecdb41.noarch::go-toolset:rhel8RHSA-2026:87246
Fixed in:2.module+el8.4.0+25201+9a419e96.noarch::go-toolset:rhel8RHSA-2026:90994
Fixed in:1.module+el8.10.0+25107+6b50279c.noarch::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.8.0+25113+a148ecc0.noarch::go-toolset:rhel8RHSA-2026:87245
golang-docs-0:1.26.10Red Hat / RHEL
Fixed in:1.module+el8.10.0+25107+6b50279c.noarch::go-toolset:rhel8RHSA-2026:86203
Fixed in:2.module+el8.4.0+25201+9a419e96.noarch::go-toolset:rhel8RHSA-2026:90994
Fixed in:4.module+el8.6.0+25114+90ecdb41.noarch::go-toolset:rhel8RHSA-2026:87246
Fixed in:4.module+el8.8.0+25113+a148ecc0.noarch::go-toolset:rhel8RHSA-2026:87245
golang-miscRed Hat / RHEL
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el9_6RHSA-2026:87043
Fixed in:0:1.26.10-1.el9_2RHSA-2026:87041
Fixed in:0:1.26.10-1.el9_4RHSA-2026:87042
Fixed in:0:1.26.10-1.el9_8RHSA-2026:86196
golang-miscRocky
Fixed in:0:1.26.10-1.el10_0RHSA-2026:87040
Fixed in:0:1.26.10-1.el10_2RHSA-2026:86093
Fixed in:0:1.26.10-1.el9_4RHSA-2026:87042
Fixed in:0:1.26.10-1.el9_8RHSA-2026:86196
Fixed in:0:1.26.10-1.el9_6RHSA-2026:87043
Fixed in:0:1.26.10-1.el9_2RHSA-2026:87041
golang-misc-0:1.26.10Rocky
Fixed in:4.module+el8.6.0+25114+90ecdb41.noarch::go-toolset:rhel8RHSA-2026:87246
Fixed in:1.module+el8.10.0+25107+6b50279c.noarch::go-toolset:rhel8RHSA-2026:86203
Fixed in:4.module+el8.8.0+25113+a148ecc0.noarch::go-toolset:rhel8RHSA-2026:87245
Fixed in:2.module+el8.4.0+25201+9a419e96.noarch::go-toolset:rhel8RHSA-2026:90994
This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploit Intelligence
0.62%probability of exploitation in 30 days
50thpercentile
Moderate risk: more likely to be exploited than 50% of all known CVEs.
References
Other references6
Related Vulnerabilities
Other CWE-675 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2019-17638 | Critical | 9.4 | 11% | - | Fix |
| CVE-2026-77860 | Low | 3.7 | 0.3% | - | Fix |
| CVE-2026-68179 | High | 8.4 | 0.2% | - | Fix |
| CVE-2025-68973 | High | 7.8 | 0.2% | - | Fix |
Common questions
How do I fix CVE-2026-78663?
Published advisories record a fix for 46 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2026-78663 being actively exploited?
Not that we know of. CVE-2026-78663 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.62% is the estimated probability that it will be exploited in the next 30 days. That is higher than 50% of all scored CVEs.
How severe is CVE-2026-78663?
CVE-2026-78663 has a CVSS v3 base score of 7.5, rated important. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-78663 affect?
Published advisories record a fix for golang-1.26 (Debian), golang-1.27 (Debian), golang-golang-x-net (Debian), golang.org/x/net (Go), and 42 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-78663
Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-10-09.