TI-2026-77662 Aliases CVE-2026-92389 GHSA-9rxv-c97x-mrjr

Direction confusion in libcurl TFTP state handling

HIGH 70CWE-200Published 2026-10-20 · Updated 2026-10-30

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: High
Impact type: Information disclosure
Confidentiality · integrity · availability: High · High · High
Fix status: Partial Red Hat: 1 fixed, 7 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-200.

Summary

libcurl's TFTP handling does not check state transitions against the requested transfer direction, affecting curl versions 8.22.0, 8.21.0, 8.20.0, 8.19.0, 8.18.0 and other versions down to 7.15.0. A malicious TFTP server can answer a download request so that the client enters transmit mode, sending data from the handle's CURLOPT_READDATA pointer. That data can include leftovers from unrelated earlier operations, such as an HTTP POST on a reused handle, and the flaw is tracked as CWE-200.

Written with Claude Haiku 5.5 from the sources below · 2026-11-07

Description from the CNA

libcurl's TFTP state machine fails to validate state transitions against the requested transfer direction, accepting opening server responses for both reads and writes interchangeably. A malicious TFTP server can respond to a download request in a way that forces the client into transmit mode, prompting libcurl to consume and transmit data from the handle's persistent `CURLOPT_READDATA` pointer - including data remaining from unrelated prior operations, such as an HTTP POST request executed on a reused handle.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00721 54th percentileScored 2026-11-07

Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 7 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
curl	curl	8.22.0 – 8.22.0; 8.21.0 – 8.21.0; 8.20.0 – 8.20.0; 8.19.0 – 8.19.0; 8.18.0 – 8.18.0; 8.17.0 – 8.17.0; 8.16.0 – 8.16.0; 8.15.0 – 8.15.0; 8.14.1 – 8.14.1; 8.14.0 – 8.14.0; 8.13.0 – 8.13.0; 8.12.1 – 8.12.1; 8.12.0 – 8.12.0; 8.11.1 – 8.11.1; 8.11.0 – 8.11.0; 8.10.1 – 8.10.1; 8.10.0 – 8.10.0; 8.9.1 – 8.9.1; 8.9.0 – 8.9.0; 8.8.0 – 8.8.0; 8.7.1 – 8.7.1; 8.7.0 – 8.7.0; 8.6.0 – 8.6.0; 8.5.0 – 8.5.0; 8.4.0 – 8.4.0; 8.3.0 – 8.3.0; 8.2.1 – 8.2.1; 8.2.0 – 8.2.0; 8.1.2 – 8.1.2; 8.1.1 – 8.1.1; 8.1.0 – 8.1.0; 8.0.1 – 8.0.1; 8.0.0 – 8.0.0; 7.88.1 – 7.88.1; 7.88.0 – 7.88.0; 7.87.0 – 7.87.0; 7.86.0 – 7.86.0; 7.85.0 – 7.85.0; 7.84.0 – 7.84.0; 7.83.1 – 7.83.1; 7.83.0 – 7.83.0; 7.82.0 – 7.82.0; 7.81.0 – 7.81.0; 7.80.0 – 7.80.0; 7.79.1 – 7.79.1; 7.79.0 – 7.79.0; 7.78.0 – 7.78.0; 7.77.0 – 7.77.0; 7.76.1 – 7.76.1; 7.76.0 – 7.76.0; 7.75.0 – 7.75.0; 7.74.0 – 7.74.0; 7.73.0 – 7.73.0; 7.72.0 – 7.72.0; 7.71.1 – 7.71.1; 7.71.0 – 7.71.0; 7.70.0 – 7.70.0; 7.69.1 – 7.69.1; 7.69.0 – 7.69.0; 7.68.0 – 7.68.0; 7.67.0 – 7.67.0; 7.66.0 – 7.66.0; 7.65.3 – 7.65.3; 7.65.2 – 7.65.2; 7.65.1 – 7.65.1; 7.65.0 – 7.65.0; 7.64.1 – 7.64.1; 7.64.0 – 7.64.0; 7.63.0 – 7.63.0; 7.62.0 – 7.62.0; 7.61.1 – 7.61.1; 7.61.0 – 7.61.0; 7.60.0 – 7.60.0; 7.59.0 – 7.59.0; 7.58.0 – 7.58.0; 7.57.0 – 7.57.0; 7.56.1 – 7.56.1; 7.56.0 – 7.56.0; 7.55.1 – 7.55.1; 7.55.0 – 7.55.0; 7.54.1 – 7.54.1; 7.54.0 – 7.54.0; 7.53.1 – 7.53.1; 7.53.0 – 7.53.0; 7.52.1 – 7.52.1; 7.52.0 – 7.52.0; 7.51.0 – 7.51.0; 7.50.3 – 7.50.3; 7.50.2 – 7.50.2; 7.50.1 – 7.50.1; 7.50.0 – 7.50.0; 7.49.1 – 7.49.1; 7.49.0 – 7.49.0; 7.48.0 – 7.48.0; 7.47.1 – 7.47.1; 7.47.0 – 7.47.0; 7.46.0 – 7.46.0; 7.45.0 – 7.45.0; 7.44.0 – 7.44.0; 7.43.0 – 7.43.0; 7.42.1 – 7.42.1; 7.42.0 – 7.42.0; 7.41.0 – 7.41.0; 7.40.0 – 7.40.0; 7.39.0 – 7.39.0; 7.38.0 – 7.38.0; 7.37.1 – 7.37.1; 7.37.0 – 7.37.0; 7.36.0 – 7.36.0; 7.35.0 – 7.35.0; 7.34.0 – 7.34.0; 7.33.0 – 7.33.0; 7.32.0 – 7.32.0; 7.31.0 – 7.31.0; 7.30.0 – 7.30.0; 7.29.0 – 7.29.0; 7.28.1 – 7.28.1; 7.28.0 – 7.28.0; 7.27.0 – 7.27.0; 7.26.0 – 7.26.0; 7.25.0 – 7.25.0; 7.24.0 – 7.24.0; 7.23.1 – 7.23.1; 7.23.0 – 7.23.0; 7.22.0 – 7.22.0; 7.21.7 – 7.21.7; 7.21.6 – 7.21.6; 7.21.5 – 7.21.5; 7.21.4 – 7.21.4; 7.21.3 – 7.21.3; 7.21.2 – 7.21.2; 7.21.1 – 7.21.1; 7.21.0 – 7.21.0; 7.20.1 – 7.20.1; 7.20.0 – 7.20.0; 7.19.7 – 7.19.7; 7.19.6 – 7.19.6; 7.19.5 – 7.19.5; 7.19.4 – 7.19.4; 7.19.3 – 7.19.3; 7.19.2 – 7.19.2; 7.19.1 – 7.19.1; 7.19.0 – 7.19.0; 7.18.2 – 7.18.2; 7.18.1 – 7.18.1; 7.18.0 – 7.18.0; 7.17.1 – 7.17.1; 7.17.0 – 7.17.0; 7.16.4 – 7.16.4; 7.16.3 – 7.16.3; 7.16.2 – 7.16.2; 7.16.1 – 7.16.1; 7.16.0 – 7.16.0; 7.15.5 – 7.15.5; 7.15.4 – 7.15.4; 7.15.3 – 7.15.3; 7.15.2 – 7.15.2; 7.15.1 – 7.15.1; 7.15.0 – 7.15.0	—	No fix listed	CNA

curl Vendorcurl Affected 8.22.0 – 8.22.0; 8.21.0 – 8.21.0; 8.20.0 – 8.20.0; 8.19.0 – 8.19.0; 8.18.0 – 8.18.0; 8.17.0 – 8.17.0; 8.16.0 – 8.16.0; 8.15.0 – 8.15.0; 8.14.1 – 8.14.1; 8.14.0 – 8.14.0; 8.13.0 – 8.13.0; 8.12.1 – 8.12.1; 8.12.0 – 8.12.0; 8.11.1 – 8.11.1; 8.11.0 – 8.11.0; 8.10.1 – 8.10.1; 8.10.0 – 8.10.0; 8.9.1 – 8.9.1; 8.9.0 – 8.9.0; 8.8.0 – 8.8.0; 8.7.1 – 8.7.1; 8.7.0 – 8.7.0; 8.6.0 – 8.6.0; 8.5.0 – 8.5.0; 8.4.0 – 8.4.0; 8.3.0 – 8.3.0; 8.2.1 – 8.2.1; 8.2.0 – 8.2.0; 8.1.2 – 8.1.2; 8.1.1 – 8.1.1; 8.1.0 – 8.1.0; 8.0.1 – 8.0.1; 8.0.0 – 8.0.0; 7.88.1 – 7.88.1; 7.88.0 – 7.88.0; 7.87.0 – 7.87.0; 7.86.0 – 7.86.0; 7.85.0 – 7.85.0; 7.84.0 – 7.84.0; 7.83.1 – 7.83.1; 7.83.0 – 7.83.0; 7.82.0 – 7.82.0; 7.81.0 – 7.81.0; 7.80.0 – 7.80.0; 7.79.1 – 7.79.1; 7.79.0 – 7.79.0; 7.78.0 – 7.78.0; 7.77.0 – 7.77.0; 7.76.1 – 7.76.1; 7.76.0 – 7.76.0; 7.75.0 – 7.75.0; 7.74.0 – 7.74.0; 7.73.0 – 7.73.0; 7.72.0 – 7.72.0; 7.71.1 – 7.71.1; 7.71.0 – 7.71.0; 7.70.0 – 7.70.0; 7.69.1 – 7.69.1; 7.69.0 – 7.69.0; 7.68.0 – 7.68.0; 7.67.0 – 7.67.0; 7.66.0 – 7.66.0; 7.65.3 – 7.65.3; 7.65.2 – 7.65.2; 7.65.1 – 7.65.1; 7.65.0 – 7.65.0; 7.64.1 – 7.64.1; 7.64.0 – 7.64.0; 7.63.0 – 7.63.0; 7.62.0 – 7.62.0; 7.61.1 – 7.61.1; 7.61.0 – 7.61.0; 7.60.0 – 7.60.0; 7.59.0 – 7.59.0; 7.58.0 – 7.58.0; 7.57.0 – 7.57.0; 7.56.1 – 7.56.1; 7.56.0 – 7.56.0; 7.55.1 – 7.55.1; 7.55.0 – 7.55.0; 7.54.1 – 7.54.1; 7.54.0 – 7.54.0; 7.53.1 – 7.53.1; 7.53.0 – 7.53.0; 7.52.1 – 7.52.1; 7.52.0 – 7.52.0; 7.51.0 – 7.51.0; 7.50.3 – 7.50.3; 7.50.2 – 7.50.2; 7.50.1 – 7.50.1; 7.50.0 – 7.50.0; 7.49.1 – 7.49.1; 7.49.0 – 7.49.0; 7.48.0 – 7.48.0; 7.47.1 – 7.47.1; 7.47.0 – 7.47.0; 7.46.0 – 7.46.0; 7.45.0 – 7.45.0; 7.44.0 – 7.44.0; 7.43.0 – 7.43.0; 7.42.1 – 7.42.1; 7.42.0 – 7.42.0; 7.41.0 – 7.41.0; 7.40.0 – 7.40.0; 7.39.0 – 7.39.0; 7.38.0 – 7.38.0; 7.37.1 – 7.37.1; 7.37.0 – 7.37.0; 7.36.0 – 7.36.0; 7.35.0 – 7.35.0; 7.34.0 – 7.34.0; 7.33.0 – 7.33.0; 7.32.0 – 7.32.0; 7.31.0 – 7.31.0; 7.30.0 – 7.30.0; 7.29.0 – 7.29.0; 7.28.1 – 7.28.1; 7.28.0 – 7.28.0; 7.27.0 – 7.27.0; 7.26.0 – 7.26.0; 7.25.0 – 7.25.0; 7.24.0 – 7.24.0; 7.23.1 – 7.23.1; 7.23.0 – 7.23.0; 7.22.0 – 7.22.0; 7.21.7 – 7.21.7; 7.21.6 – 7.21.6; 7.21.5 – 7.21.5; 7.21.4 – 7.21.4; 7.21.3 – 7.21.3; 7.21.2 – 7.21.2; 7.21.1 – 7.21.1; 7.21.0 – 7.21.0; 7.20.1 – 7.20.1; 7.20.0 – 7.20.0; 7.19.7 – 7.19.7; 7.19.6 – 7.19.6; 7.19.5 – 7.19.5; 7.19.4 – 7.19.4; 7.19.3 – 7.19.3; 7.19.2 – 7.19.2; 7.19.1 – 7.19.1; 7.19.0 – 7.19.0; 7.18.2 – 7.18.2; 7.18.1 – 7.18.1; 7.18.0 – 7.18.0; 7.17.1 – 7.17.1; 7.17.0 – 7.17.0; 7.16.4 – 7.16.4; 7.16.3 – 7.16.3; 7.16.2 – 7.16.2; 7.16.1 – 7.16.1; 7.16.0 – 7.16.0; 7.15.5 – 7.15.5; 7.15.4 – 7.15.4; 7.15.3 – 7.15.3; 7.15.2 – 7.15.2; 7.15.1 – 7.15.1; 7.15.0 – 7.15.0 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:haxx:curl::::::::	—	—	Haxx

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:* Versions — — ·Haxx

Remediation

The sources list no fixed version for curl. Red Hat fixes it in Red Hat Hardened Images through RHSA-2026:82895, released 2026-10-14. Red Hat plans no fix for Red Hat Enterprise Linux 6 and 7, and has none available for Red Hat Enterprise Linux 8, 9 and 10 and Satellite 6.

Written with Claude Haiku 5.5 from the sources below · 2026-11-07

Red Hat 1 advisory

RHSA-2026:82895 Released 2026-10-14 · Red Hat rating Important
Red Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images curl-8.23.0-0.1.hum1@aarch64, curl-8.23.0-0.1.hum1@s390x, curl-8.23.0-0.1.hum1@src +10

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet
Red Hat Enterprise Linux 6	Affected	No fix planned: Out of support scope
Red Hat Enterprise Linux 7	Affected	No fix planned: Out of support scope
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet
Red Hat OpenShift AI (RHOAI)	Affected	—
Red Hat Satellite 6	Affected	No fix yet: Fix deferred
Red Hat Hardened Images	Fixed	RHSA-2026:82895

Not affected: 6 products

Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 9
Red Hat Hardened Images
Red Hat JBoss Core Services
Red Hat OpenShift AI (RHOAI)
Red Hat Satellite 6

Timeline

2026-10-21 Threatist record created from CVE-2026-92389
2026-10-21 Alias added: GHSA-9rxv-c97x-mrjr
2026-10-23 Affected versions changed · Red Hat
2026-10-30 CVSS score added · CISA ADP
2026-10-30 Weakness changed · CISA ADP
2026-10-30 CISA SSVC decision points changed
2026-10-30 Priority changed: LOW → HIGH
2026-10-31 EPSS moved to the 50th–90th percentile
2026-11-07 Affected versions changed · Red Hat

References

Other 3

TI-2023-19922 Out-of-bounds write in curl CVSS 3.1CRITICAL 9.8
TI-2026-16162 Negotiate ambient user conn reuse CVSS 3.1CRITICAL 9.8
TI-2026-10231 cross-origin Digest auth state leak CVSS 3.1CRITICAL 9.8
TI-2026-09063 HTTP/2 stream-dependency tree UAF CVSS 3.1CRITICAL 9.8
TI-2026-07976 stale proxy password leak CVSS 3.1CRITICAL 9.8
TI-2026-07845 SASL double-free CVSS 3.1CRITICAL 9.8

See all 103 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences